Today's Messages (OFF)  | Unanswered Messages (ON)

Forum: Misc. Ham Forum
 Topic: Hello, everyone
Hello, everyone [message #1080] Sat, 12 November 2011 12:46
bg7iae  is currently offline bg7iae
Messages: 1
Registered: November 2011
Junior Member
Hello HAM, Everyone! i from china, SZ city. Very pleased to be here. PRO5150 CPS here? 73!


de bg7iae.
bg7iae@szham.org
Forum: Icom Mods
 Topic: ICOM IC-706 MARS/CAP Modification
ICOM IC-706 MARS/CAP Modification [message #3041] Wed, 11 June 2014 00:32
root  is currently offline root
Messages: 145
Registered: December 2004
Senior Member
Tools required:
l #0 Philips head screwdriver
l 10 - 15 watt pencil tip soldering iron
l Magnifying glass
l Tweezers
Remove the TOP cover by removing three Philips head screws on the top and one on each side. Move the speaker bracket out of the way. Locate D-59, this is a three terminal SMD diode in an SOT package, about 1 x 3 mm (with the radio front panel oriented towards you, D-59 is located in a row of SMD diodes just to the right of the ribbon cable header above the 9 MHz SSB filter FL-30. There are pads for 5 diodes with only three installed. D-59 is the second from the left).
Using tweezers and a low-wattage soldering iron (and magnifying glass, if necessary) remove D-59 by applying some heat to the single leg side of the device while lifting gently, then apply heat to the other two legs and removing the device. Be careful not to apply too much heat, not to rip or burn any traces or not to leave excess solder on the PCB. Replace the speaker bracket and top cover.
Apply power and reset the microprocessor.
TX = 1600 kHz - 54.00 MHz and 118.000 - 174.000 MHz
De James KG7FU
 Topic: ICOM IC-04 Out of Band Modification
ICOM IC-04 Out of Band Modification [message #3040] Wed, 11 June 2014 00:27
root  is currently offline root
Messages: 145
Registered: December 2004
Senior Member
Out of Band Modification for the Icom IC-04

1. On the logic matrix, remove D402.
2. Add D402, D403 and D404 with the cathode at 4 o'clock and the anode at 12 o'clock. (You may use any signal diode such
as 1N914)
3. Add D405 with the cathode at 8 o'clock and the anode at 12 o'clock.
4. If you have a newer 04AT, the VCO cover will have holes in it that allow access to the tuning coils. If you have an older
04AT you will have to cut a hole in the VCO cover using a pair of small diagonals (be careful!).
5. Re-tune the VCO to cover your desired frequency spread. My 04AT goes from 441 to 473 MHz, which is pretty good.
6. Any frequency may be entered directly on the keypad (starting with the 10 MHz digit).
 Topic: Icom IC-706mkiig IF-SDR
Icom IC-706mkiig IF-SDR [message #3032] Mon, 10 March 2014 02:07
root  is currently offline root
Messages: 145
Registered: December 2004
Senior Member
Next video will be a IC706 with TV dongle connected to the IF, it works very well.

Well here's part two for what it's worth.


It's quite easy to pick up the 69MHz intermediate frequency in an Icom 706 mk1. There are two plated holes in the track which carry the IF signal so just by inserting the inner of the coax into one of these it can be picked up by the dongle.

http://youtu.be/vY8xlmuX21s

The TV dongle accepts this signal and if it is then tuned to 69MHz you are then able to see the IF on the spectrum display and waterfall. The waterfall is not shown here . With the dongle I have here I am able 1.8MHz of spectrum but I can also zoom-in. There are lots of features in the software most impressive is the filtering.

Software used here is SDR#, another that works with the dongle is HDSDR.

So why would you do this? Well it adds a whole new dimension to an otherwise boring black box.

Try it and find out.

There is no reason, of course, why this set-up can not be applied to other rigs with an IF over 60MHz (dongle doesn't go lower).

Hope you find this of interest.

Sorry video's not up to much.

If you want more info ask me at the Club.

Next will be Powersdr-IF and CAT control of the IC706.



SDR-IF Part Three

I think that this set-up is the most likely to appeal to members.

Here I am using my IC 706 Mk1, the intermediate frequency of which is feed to a home-brewed SDR which I mostly use on Six and Four Meters, so it's ideal to receive the 69MHz IF from the 706.



The software in use here is Ham Radio Deluxe, PowerSDR-IF and Rocky.

HRD is used for the CAT control of the 706. PowerSDR-IF then connects to HRD.

http://youtu.be/0SI2rggbiFI

The waterfall display of Rocky is used to view CW, it is not connected to the 706 or the other software, using the sound card output only.

In the video I'm just tuning around the bands mostly using the mouse to click on the spectrum display/pan-adapter of PowerSDR-IF but also using both the slider and DX-spots of HRD. Of course it's also possible to use the 706 tuning knob but this seems a bit "old hat".

The pan-adapter reveals some pretty wide signals, some very clean ones, some with poor carrier suppression, sweepers, odd QRM sources and more. There is no CW filter in the 706 so the SDR output is the only way to receive CW properly.

Hope this is of interest.

If you want more info ask me at the club or post here.



I have been asked by a Club member for information on the 1st IF tap point that I used to feed the
RTL TV dongle from my IC706 Mk1.
The photos below should help.



"It's quite easy to pick up the 69MHz intermediate frequency in an Icom 706 mk1. There are two plated holes in the track which carry the IF signal so just by inserting the inner of the coax into one of these it can be picked up by the dongle."

http://www.hamradio.cc/images/forum/mods/icom_706_mkiig_if_sdr.jpg

Use the hole towards the front panel. BE CAREFUL AND TRY IT BEFORE SOLDERING.

http://www.hamradio.cc/images/forum/mods/icom_706_mkiig_if_sdr_.jpg

Daniel Fourlas - sv1jcz
 Topic: ICOM R7000 Display Issue / R7000 Sensitivity Problem
ICOM R7000 Display Issue / R7000 Sensitivity Problem [message #3004] Mon, 02 September 2013 13:29
root  is currently offline root
Messages: 145
Registered: December 2004
Senior Member
If you are having trouble with you Icom R7000 display being flaky
and then a sudden decrease in sensitivity try the following:


PROBLEM: ICOM R7000 radios that are used 24 hours a day for a long time
(2 years ) when shut off the display will become flaky and it
is also possible for a lost in overall gain (3 to 40 db).

SOLUTIONS: Officially there is ICOM ECO SB# 9288-004, attached below.

Unofficially from Tech who repairs R7000
The ECO does help the display problem, but most likely
it is not the problem. *

* note repairing your own radio my void you warranty and only
allow a qualified technician to do the job, otherwise damage
could happen to your R7000. If the VCO does not track then a
major alignment would have to be done after. Check the
ICOM IC-R7000 Service Manual for more details before starting
this repair, and to make sure I have not made any typing errors
you should get a copy of the ECO from ICOM !

1st SOLUTION:
Replace on the DC to DC Board the following capacitor.
Check the noise with an oscilloscope on both sides of
R3, if the noise is not way down on one side then
replace C2 a 33uf 16V capacitor. Noise feedback
can decrease the overall sensitivity of the R7000.

Replace on the Display Board
C19 and C20 a 10 uf 16VDC capacitor

I found that on my R7000 C19 & C20 were the cause of my
display problems. They are 10 uf electrolytic capacitors
that are lemon yellow pc mounted units, when they go bad
the base of the yellow caps change to a brown color.

I put in the following ECO first but it did not help. If
you look at the service manual you will see that the ECO
values are on the schematic but my unit had the old values.
I suggest that you check the above first, it is a lot easier
to do, C19/C20 can be done in 10-15 min while the ECO will
take about a hour.


2nd SOLUTION: The ECO


ICOM America, INc
2380-116th Ave, N.E.
Bellevue, Washington 98004
206-454-7619


SERVICE BULLETIN


UNIT MODEL R7000
SB# 9288-004
EFFECTIVE DATE 4/1/88
SERIAL # AFFECTED: ALL
PRODUCT GROUP: Amateur

BACKGROUND INFORMATION:
Display failure do to weak components

TECHNICAL INFORMATION:
Improvement in DC to DC converter and display power supply.

PARTS AFFECTED BOARD TYPE CHANGE TO NEW PART NUMBER
Q1/Q2 2SC 1214 DC to DC Board 2SC 2655 906-00385
R1/R2 3.3 KOHM DC to DC Board 5.16 K 915-01173
C3/C4 PF DC to DC Board 0.001 MF 50V 918-01500
ceramic cap
Q11/Q12 Display Board 2SC2655 906-00385
R31/R32 3.3KOHM Display 5.16k Ohm 915-01173
C13/C16 Display 0.001 MF 918-01500

DETAIL PROCEDURE:

1. Remove top and bottom cover.
2. Remove front panel sub-assembly from main chassis of radio
3. Remove the DC to DC board and replace components as listed
4. Reinstall DC to DC board.
5. Replace front panel sub-assembly onto main chassis of radio
6. Replace top and bottom covers.

ESTIMATE TIME TO COMPLETE IS 1 hour

 Topic: ICOM IC-R7000 Repair - Capacitors
ICOM IC-R7000 Repair - Capacitors [message #2999] Wed, 10 July 2013 11:01
root  is currently offline root
Messages: 145
Registered: December 2004
Senior Member
** There is no retuning of the IC-R7000 radio required as the capacitors being changed are power supply related, or audio coupling/decoupling.

** Installation Time is approximately 4-6 hours from start to finish for an experienced technician. For all others, take you time and enjoy its a great project!

The kit is comprised of the following capacitors (118 in all):


.47uf 50V - Qty 14

.47uf 50V BP - Qty 2

1uf 50V - Qty 5

2.2uf 6.3V 7mm - Qty1

2.2uf 50V - Qty 1

3.3uf 50V - Qty 4

4.7uf 50V - Qty 5

4.7uf 25V 7mm - Qty 1

10uf 16V 7mm - Qty 3

10uf 16V - Qty 35

22uf 10V - Qty 5

22uf 25V - Qty 1

33uf 16V - Qty 3

47uf 16V - Qty 12

47uf 6.3/10V 7mm - Qty 2

100uf 16V - Qty 7

100uf 25V - Qty 4

220uf 10V - Qty 4

470uf 16V - Qty 7

4700uf 35V - Qty 2

[Updated on: Wed, 10 July 2013 11:02]

 Topic: ICOM IC-R1 Keypad Problems
ICOM IC-R1 Keypad Problems [message #2998] Tue, 09 July 2013 00:24
root  is currently offline root
Messages: 145
Registered: December 2004
Senior Member
If your keypad goes south on the IC-R1, open the unit,take out the 6 screws on the board with the speaker de-solder the speaker and both boards come out together.where the 8 solder joints join the daughter board to the backboard look at those joints under mag.what you will notice first is one set of#s 1479 etc. when you loose a contact between these boards you will loose a row of buttons.......use a small gun,,don't need to de-solder these just add more .....take care not to solder all legs together as this would be bad!!! also turn board over and do the other side...don't forget when your backing out to re-solder the speaker leads.......been there done that ....take your time don't be watching the kids close door and go for it......partspig
 Topic: IC-476 and PRO LCD backlight repair mod
IC-476 and PRO LCD backlight repair mod [message #1484] Thu, 06 September 2012 02:07
root  is currently offline root
Messages: 145
Registered: December 2004
Senior Member
IC-746 Backlight Repair / IC-746PRO Backlight Repair

Here is how I mounted a TO-220 type transistor in place of the original backlight driver transistor, Q302. An ECG/NTE 378 in the TO-220 case style will substitute for the surface mount 2SB1201 that came with the IC-746.
You will need to unsolder and remove the shield, drill a hole in the case and mount the new transistor.

This provides a larger heatsink and a transistor with more thermal dissipation ability. You will need to isolate the transistor from the shield using the insulating kit that comes with the transistor. Be sure and use thermal heatsink silicone grease.

After mounting the transistor, solder the shield back into place.

You will need to run small jumper leads soldered to the NTE-378 and run over to the pads on the PC board where Q302 was lohoneyed. Looking down from the top where Q302 was lohoneyed, the lead configuration is Base Collector Emitter from left to right. The Base pad is close to the shield, and the Emitter pad connects to L301. Collector goes to the center pad.

index.php?t=getfile&id=59&private=0

E. Kirk Ellis, KI4RK

[Updated on: Thu, 06 September 2012 02:07]

 Topic: IC-746 PRO Repair - Low TX Power on all Bands
IC-746 PRO Repair - Low TX Power on all Bands [message #1236] Tue, 17 January 2012 00:23
root  is currently offline root
Messages: 145
Registered: December 2004
Senior Member
On Checking an IC-746PRO with low output power, it was found that the pre-predriver transistor tr Q1 (2SK2973)had overheated because of insufficient heatsinking (this has been covered many times before). The transistor was replaced only to find no improvement. Further investigation proved that the small choke L2 100uh had gone open circuit.

I replaced the choke and all has been well with 100w output on all bands. Check the standing current of this transistor as the specs per the w/manual is incorrect. The standing current of 500ma as per another published article has proved perfect.

The IC746-PRO is again functioning perfect - better than before!

Author: zS2ACP
 Topic: Icom R71 Synchronous detector
Icom R71 Synchronous detector [message #1083] Tue, 15 November 2011 01:44
root  is currently offline root
Messages: 145
Registered: December 2004
Senior Member
Author: Dayle Edwards

The Icom R71 in all its flavours is one of the best performing receivers of all time, and its AM reception can be improved enormously with the inclusion of a synchronous detector. As it happens, this is very easy to do, as much of the necessary circuitry is already present, in the form of a balanced SSB detector and carrier insertion oscillators, used in the existing SSB modes.

Looking at the SD circuit, it comprises nothing more than a dual opamp. The Icom SSB product detector output, when close to zero beat with the wanted AM signal will contain the difference frequencies, either a audio heterodyne, or when locked, a DC voltage. The DC voltage is a function of any phase difference between the two inputs to the mixer, the carrier insertion oscillator, and the IF ouput. This voltage is heavily filtered to remove as much audio as possible , amplified by opamp A, and the resultant is fed to the varicap diode frequency shift of the 30.2 MHz master oscillator on the Icom PLL board, thereby correcting any phase error to the received signal. Any mistuning will result in a hetero-dyne from the mixer output, this is amplified by opamp B, rectified and switches the display "tune" segment via TR1/TR2. Diode D3 allows the Synch board to coexist with the FM option if fitted... this also uses the "TUNE" segment.. The "TUNE" display segment will activate within 20 cycles or so from the center frequency, giving a lock indihoneyion when correctly tuned.

The Synch detector will lock well on signals below the noise, and can exhibit a dramatic improvement on many marginal signals. With stronger signals, the audio quality can be very much improved, selective sideband fading or cancellation can be almost eliminated, and any noise is held to the level of the wanted signal. The Synch detector uses selectable sideband, simply by selecting either USB, or LSB, all installed filters able to be used with this design, as too the Pass Band Tuning and notch filter. It is important to note, the capture range of the design is limited to around 20 Hz, it is only required to lock the phase, not the frequency, so correct initial tuning is critical, the lock range being approximately 80 Hz. The limited bandwidth also allows normal SSB/CW modes to be used with no interaction from the synch detector which is permanently active. Normal AM remains selectable from the front panel.

The board will mount on the two pillars used when installing the FM option, or if this is already installed, it will piggy back above using longer screws and spacers. The unit is wired as follows.

REMOVE POWER FROM THE RADIO.

The signal input is got from R157, rear right of main circuit board.
The minus 10 volts is got from R197, rear center between the crystal and FM option connector.
The 8 volt plus is found at jumper W46, center on the circuit board opposite the regulator chip.
The tuning voltage will connect to R105 extreme right lead on the PLL board, rear right hand side.
The indihoneyor voltage connects to the RED wire in the two pin connector for the FM option The circuit boards need not be removed for these connections to be made, it is sufficient to carefully solder the wires to the exposed resistor leads. All added wires are at DC only, so no additional birdies, spurs or noises are created.

Initial setup:

Connect a voltmeter to IC1 pin 1, and with the radio tuned off a station at around 25MHz, slowly adjust VR1 to obtain a reading of near 3.5 volts. The unit is now ready for use. Tune in a weak AM station in SSB mode, slowly tune for a zero beat. At some point, the carrier will lock, the audio will become clear and natural sounding, and the "TUNE" segment should light. Unless the ICOM high stability VXO option is fitted, its likely each station will need to be manually tuned slightly up or down from the set frequency indihoneyed. Remember, the R71 tunes in 10 Hz steps, these are not recorded on the frequency display.

http://www.hamradio.cc/images/forum/mods/ICOM-R71_1.jpg

http://www.hamradio.cc/images/forum/mods/ICOM-ic-r71_synch.gif

[Updated on: Tue, 15 November 2011 01:45]

 Topic: ICOM IC-751 Mod Unlock Transmitter
ICOM IC-751 Mod Unlock Transmitter [message #1043] Sat, 15 October 2011 17:15
root  is currently offline root
Messages: 145
Registered: December 2004
Senior Member
ICOM IC-751 Mod

Locate the RF board on the side of the radio and cut the black wire going to pin 1 of jack 2. Your transmitter is now unlocked. (This mod also described in "73 Magazine", July 1985 p. 12.)
 Topic: ICOM IC-745 Mod Unlock Transmitter
ICOM IC-745 Mod Unlock Transmitter [message #1042] Sat, 15 October 2011 17:12
root  is currently offline root
Messages: 145
Registered: December 2004
Senior Member
ICOM IC-745 Mod

Locate the RF board on the side of the radio and cut the light brown wire at jack 7., which is going to pin 1. Your transmitter is now unlocked.
 Topic: ICOM IC-720 Mod Transmitter Unlock
ICOM IC-720 Mod Transmitter Unlock [message #1041] Sat, 15 October 2011 17:11
root  is currently offline root
Messages: 145
Registered: December 2004
Senior Member
ICOM IC-720 Mod

Transmitter is unlocked by snipping the light blue wire that's at the very end of the top hatch cover to the left middle side of the
transceiver.
 Topic: ICOM IC-735 Mod - Unlock Transmitter
ICOM IC-735 Mod - Unlock Transmitter [message #1040] Sat, 15 October 2011 17:10
root  is currently offline root
Messages: 145
Registered: December 2004
Senior Member
ICOM IC-735 Transmitter Mod

To unlock the transmitter: cut diodes D33 and D34 that are standing on end near the microprocessor section toward the rear top of the radio.
 Topic: Icom IC-25 expanded RF (keyboard mod)
Icom IC-25 expanded RF (keyboard mod) [message #785] Wed, 17 August 2011 23:36
root  is currently offline root
Messages: 145
Registered: December 2004
Senior Member
1. Set offset to 0.0

2. Select VFO (A).

3. Press and hold [SIMP/DUP] and [NOR/REV].

4. Dial in desired frequency.

5. Release [SIMP/DUP] button.

6. Select the other VFO (B).

7. Repeat steps 3, 4, and 5

if VFO (B) can not be set, transfer VFO (A) VFO (B) using the [WRITE] button as described on page 7, item 6, of the owners manual.

Note: [SIMP/DUP] must be out when the VFO is changed.

If the tuning knob is turned again, the radio will revert back within the normal band range.
 Topic: IC-R7000 Audio Modifications
IC-R7000 Audio Modifications [message #385] Thu, 26 May 2011 23:08
root  is currently offline root
Messages: 145
Registered: December 2004
Senior Member
The following modifications provide the following facilities.

- base band audio output, to utilizing digital transmissions such as AIS etc.
- a CTCSS filter insertion point, to eliminate annoying hum from the speaker Both these mods are best tackled at the same time.

1. Undo the screws holding the IF unit in position. Disconnect interconnecting cables.

2. As as indicated by the circuit diagram & board layout the baseband signal is taken from the discriminator output via a 10K resistor. Solder the 10K resistor to R97 on the solder side of the board and solder the other side to the inner braid of some thin audio coax cable. Connect the other end to the spare connector on the rear panel. Use some 3mm heat-shrink tube to cover the 10K resistor & hold in position with some hot glue. Connect the earth braid to a convenient earthing point with some insulated wire.

3. Remove C86 & connect some thin stereo coaxial cable (red = filter input & yellow=filter output) to each now empty pad. Connect the earth braid to a convenient earthing point with some insulated wire. The coaxial cable should be long enough to reach where the filter is installed. In my case I put this at the bottom where the IR receiver & Speech unit can be mounted.

4. Re-install the IF unit by screwing it in position & restoring the interconnecting cables.

5. An essential requirement is that both the input & output of the filter are capacitively coupled. For the filter unit, I used a recovered a CTCSS board from a Motorola SYNTRX FM radio. It contains the essential HP filter required to filter out the CTCSS tones, but in addition it contains a LP filter, which I will use to feed a CTCSS detector/display ( for info purposes). I used a hacksaw to cut off only the circuitry that I wanted. Alternatively a filter could be home brewed.

6. A switch could be provided to to enable straight through audio should this be required.

http://www.hamradio.cc//images/forum/mods/IC-R7000_baseband_CTCSS_modifications-1.jpg
Illustration 1: IF Unit modifications

http://www.hamradio.cc//images/forum/mods/IC-R7000_baseband_CTCSS_modifications-2.jpg
Illustration 2: IF unit modification locations

http://www.hamradio.cc//images/forum/mods/IC-R7000_baseband_CTCSS_modifications-3.jpg
Illustration 3: Typical CTCSS filterboard
 Topic: Icom IC-9100 Mod - Partial TX
Icom IC-9100 Mod - Partial TX [message #340] Tue, 05 April 2011 00:21
root  is currently offline root
Messages: 145
Registered: December 2004
Senior Member
There are several ranges that can be selected by arranging diodes. First you can choose to only open up some areas and leave other frequencies (non amateur bands) locked.

40m amateur bands expansion (7.00MHz - 7.300MHz) : remove diode D1517
60m band expansion (5.255MHz - 5.405MHz) : remove diode D1515

index.php?t=getfile&id=42&private=0

Assemble radio.

Reset radio (full reset) by holding [F-INP ENT] and [M-CLR] and turn power ON.

[Updated on: Tue, 05 April 2011 00:26]

 Topic: Icom IC-9100 Mod - RX Expansion
Icom IC-9100 Mod - RX Expansion [message #339] Tue, 05 April 2011 00:13
root  is currently offline root
Messages: 145
Registered: December 2004
Senior Member
RX-range: 30kHz - 60MHz, 180MHz - 174MHz, 420MHz - 480MHz, 1240MHz - 1320MHz

Locate diodes behind front panel.

Remove diodes D1504 and D1505 for full RX.

Assemble radio.

Reset radio (full reset) by holding [F-INP ENT] and [M-CLR] and turn power ON.

index.php?t=getfile&id=41&private=0

 Topic: AM transmitter enable for the Icom IC-745
AM transmitter enable for the Icom IC-745 [message #310] Sun, 23 January 2011 01:23
root  is currently offline root
Messages: 145
Registered: December 2004
Senior Member
Intro:

After returning home from purchasing a used (but in good condition) ICOM IC-745, initial check out revealed the transmitter did not function in AM transmit mode. A look and the owners manual revealed: "AM Receive Only" What!!!??? This is supposed to be an ALL MODE RADIO! In reality the words used were..."ALL BAND HF RADIO"

After analyzing this perplex situation I came to the conclusion ICOM must have been doing their part in trying to save precious spectral bandwidth by not incorporating AM transmit in this particular model.
No one really utilizes AM mode these days (including myself) but this radio has every mode ever conceived and to leave AM transmit out really aggravated me!

Below is the Mod of Mods for IC-745 owners:

(All Modifications administered to the "MAIN UNIT" board located under the top cover of the radio.) (Except for R21 Removal on the logic board for the Power Mod.)
Parts List:

8 pin diodes. Factory Diodes are P/N 1SS53. 1N914's are fine.
3 10k resistors 1/4 watt.
1 NPN TO-92 pkg. switching TX, 2N3904 or equivalent is fine.
Source Voltage Terminology and Locations:

R8 = 8 Volt Receive Mode Source
AM8 = 8 Volt AM Mode Source
FM8 = 8 Volt FM Mode Source
CW8 = 8 Volt CW Mode Source
RY8 = 8 Volt RTTY Mode Source
USB8 = 8 Volt USB Mode Source
LSB8 = 8 Volt LSB Mode Source
                          ______________________ 
                         |                     | 
        "J7"      Pin #1 | O O O O O O O O O O | Pin #10 
     Main Board          |_____________________| 
                           | | | | | | | | | | 
                           --- --- | | --- --- 
                            A   R  U L  C   F 
                            M   Y  S S  W   M 
                            8   8  B B  8   8 
                                   8 8 
 
                               ----------- 
        "J21"           Pin #1 | O O O O | Pin #4 
       Main Board              ----------- 
                                 | | | | 
                                 ------- 
                                   R8 

THE MOD

1.

Pull up the anode end of Diode D44. (located by TX Q39) Build the additional circuit below. This will enable the B+ to the product detector and 9 Mhz BFO oscillator.
The 9Mhz osc will now be working for AM transmit as well as BFO Rec.

       
                      C 
                        o to AM8  (Where the Anode of D44 was) 
                         \\ 
                          \\| B       10K      1N914 
                           |------\\/\\/\\/\\/-----|<-----o to R8 
                          /| 
      to R239 o----|<----/    2N3904 or Equivalent 
                  D44    E 

2.

Remove R66. (Located by TX Q13) Relocate and solder one end of R66 to the bottom of the board. (The end that goes to R23 and R30)

(The schematic shows a "BREAK" in the land. By removing the resistor from the PC board this simulates the break.)

Solder two 1N914's to the other end of R66. (Cathode ends of course)

Note: All pin assemblies will be connected on the underside of the Main Unit PC board.

This is part of the Mode selection process, and turns off the mike shunt in AM mode. (So audio can pass to the Balanced Modulator.)
      to R23 & R30   o-----\\/\\/\\/--:----|<----o   Anode to CW8 
                                   | 
                            R66    :----|<----o   Anode to RY8 
                            10K     pair 1N914's (add) 

3.

Solder one 1N914 diode (Cathode end) to the cathode connection of D15 (by TX Q19) under the board. Connect the anode to AM8.
This will enable the B+ to the Mic Amp stages and VOX ckts.
              to R31 (10K) 
               ^ 
               | 
               | 
              ___ 
             break 
              ___ 
               |           D15 
               |------------|<----------------o Goes to 8 Volt LSB  
      Source 
               |------------|<----------------o Connect to AM8  
      Source 
               | 
               |           1N914 (add) 
       
              to R100 (100 Ohms) 

4.

Remove R31 (Located by TX Q8) Relocate and solder one end of R31 to the bottom of the board. (The end that goes to R30 and the base of Q8)

(The schematic shows a "BREAK" in the land. By removing the resistor from the PC board this simulates the break.)

Solder Three 1N914's to the other end of R31. (Cathode ends) Tie the Anode ends to LSB8, USB8, FM8. Function: This portion of the mod will turn Q8 off in the AM mode to unbalance the balanced Modulator (IC1) for AM full carrier operation.
                       C 
                        o                      3 1N914's (add) 
                         \\ 
                (Q8)      \\| B         R31     |--|<-----o to  LSB8 
              Bal/^Bal     |---------\\/\\/\\/\\/--|--|<-----o to  USB8 
              switch      /|  |   |            |--|<-----o to  FM8 
                for      /    |   | 
                IC1     o     \\   \\ 
                      E       /   / 
                          R29 \\   \\ R30 
                              /   / 
                              |   |     R's=10K's 
                             ___  | 
                              _   o 

5.

Remove R24 (Located by TX Q7, "Mike Shunt Ckt") Solder a 1N914 Diode (Cathode end) into one of the pc holes that R24 came out of. (The one end that connects to R65 by Xtal X1.) Tie the anode to AM8.
This will enable the 9 Mhz CW xtal to generate the correct center frequency for AM.
          -- 
       o-||||--->|-o 
          --  | 
          X1  \\ 
              / 
          R64 \\                         1N914 (add) 
          10K /       R65 
              |-----\\/\\/\\/\\--------------|<------o AM8 
             ___      220     | 
         C44 ___              ---|<---o to CW8 
         47pf | 
             ---                D13 
              - 

6.

AM Power Level Adjust (optional)Due to the duty cycle requirements of AM, output power of 40/50 Watts RMS should be the limit. Use the Front panel RF adj to reduce the output from 100 Watts or do the following:
1.

Connect a small 22 gauge (or so) wire from AM8 to the anode of Diode D26 by TX Q20. Add a series 10K resistor.
                AM8 o------\\/\\/\\/\\---------- o-->|-----o to Q20 
                             10K             |  D26 
               |________________________|    o 
                        Add this             o S1 
                                             | 

2.

Set the 50/100 Watt power switch (S1) in the 100 Watt Position if you desire 100 watt operation of SSB,CW,RTTY.
3.

Adjust R116 (in AM xmit mode) for a power output of 40 Watts RMS.
4.

What were doing here is using the 50 Watt low power ckt as the AM power adjustment control.
Paralleling another connection to FM8 will allow FM to be reduced in similar fashion (as well as AM) instead of the factory 100% duty cycle.
                FM8 o---->|-------/\\/\\/\\/----o 
                        1N914    |  10K      | 
                AM8 o---->|-------           o-->|-----o to Q20 
                        1N914                |  D26 
                                             o 
                                             o S1 
                                             | 

Note: When 10 Meters is selected port 28M (pin 47, IC3 on the logic unit) goes high, this turns on pin diode D27 on the main unit. This ultimately turns on the 50 watt (low Power) ckt allowing only low power operation from 28-30 Mhz?
I don't know why Icom did this? My guess is for 10 Meter FM overlooking the fact SSB/CW will be running reduced also. You may want to remove R21 (10K) on the logic board to remedy this situation. After R21 is removed you can limit the duty cycle on AM & FM as follows:
          FM8 o----\\/\\/\\/\\----->|---- 
                     10K   |   D27   | 
                           |         | 
          AM8 o----\\/\\/\\/\\----->|-------o to Q20 
                     10K   |   D26 
                           | 
                           o 
                           o  S1 
                           | 

Low power Adjustment R116 will now adjust output power for FM as well as AM.

Operation/conclusion:

The above AM/FM power mod is recommended. Higher power levels (Greater then 70/80 Watts RMS) result in severe distortion of the AM output signal.

Surprisingly the audio quality is quite good on AM xmit. (40/50 Watts) Several on the air discerning ears concluded the fidelity was quite acceptable. (Even from the Johnson Viking Guys on 3.880 (+-)).

For you skeptics wondering how an AM signal can sound acceptable through a 3Khz wide 455Khz SSB filter....................???

A quick turn to the schematic on the IF board depicts filter F-I1. (Ceramic filter CFW-455IT) This filter is a 6Khz wide ceramic filter used for AM receive mode. After the completion of the Mod this filter will be used for AM xmit also, by default! >>> It's in there!!

(Wasn't that a commercial once?)

Filter F-I2 (ceramic Filter CFT-455K14) or the optional FL-44A (SSB filter) is in operation for all other modes except FM. The optional FM board employs it's own filter arrangement.

That's it. Your all mode radio is now all mode!

73 Paul N2FAN

*05/2000

I have scanned the Main Board and Logic Board to depict the electrical changes made to the circuits. I tried to nicely re-label all the changes using VISIO technical, but I ran into some offset problems.

The hand written changes will have to do for now until I can get Visio to work right. If you have any questions about this Mod feel free to ask via e-mail only (I'm hard to get a hold of) e-mail = n2fan@glensummit.com

This is not an easy cut the wire mod, you will need to have some good electronic technician skills. PhD's forget it! ...............

This Mod works, I still have my IC-745 after 8 years!

73 and Good Luck!
 Topic: ICOM IC-756 Expand Transmit Frequency Mod
ICOM IC-756 Expand Transmit Frequency Mod [message #307] Sun, 16 January 2011 23:58
root  is currently offline root
Messages: 145
Registered: December 2004
Senior Member
Notice: ICOM does not guarantee this to expand the frequency.

How to change full coverage transmit:
Remove the W805 jumper chip on MAIN board with a soldering iron.
Locate the jumper matrix located near the IC803.

What to do:
Remove bottom cover of ICOM IC-756. On the MAIN board you will see IF filters and a daughter board (DSP filter) on the right side. The W805 jumper and IC803 chip is lohoneyed under the DSP board. You have to remove the DSP board (carefully) and look for the part labeled IC803 and the line of jumpers (little green parts). When done, unsolder the W805 jumper. Install the DSP board and put the bottom cover back.
                     ---------------
         [W801]     |               |
         [W802]     |               |
         [W803]     |    IC 803     |
         [W804]     |               |
REMOVE==>[W805]     |     CHIP      |
         [W806]     |               |
         [W807]      ---------------
         [W808]

This info is from the ICOM SERVICE INFORMATION sheet.
http://www.hamradio.cc/images/forum/mods/ICOM-ic-756tx-mod.jpg

[Updated on: Mon, 17 January 2011 00:02]

 Topic: Icom IC-77 Mars Mod - tx expansion
Icom IC-77 Mars Mod - tx expansion [message #306] Wed, 12 January 2011 04:03
root  is currently offline root
Messages: 145
Registered: December 2004
Senior Member
For Ham Mod remove the lower RIGHT diode (d14) from the pcb behind the lock button. it looks like this:

[d12] [d13]
[d11] [d14]

For TX expansion you have to leave (d11) intact and take the diode (d14) that you removed and install it at (d13).

http://www.hamradio.cc/images/forum/mods/icom_ic-77_Ham-TX-exp-1.jpg

If the diodes are all gone and no original diodes can be obtained normal 1N4007 diodes or similar can be used.

http://www.hamradio.cc/images/forum/mods/icom_ic-77_Ham-TX-exp-2.jpg

http://www.hamradio.cc/images/forum/mods/icom_ic-77_Ham-TX-exp-3.jpg

Author: V51JP

[Updated on: Wed, 12 January 2011 04:06]

 Topic: Icom IC-A20 Mod Extend Frequency
Icom IC-A20 Mod Extend Frequency [message #305] Tue, 11 January 2011 01:20
root  is currently offline root
Messages: 145
Registered: December 2004
Senior Member
To extend frequency range (high end)from 135.975 to 136.975 MHz on the Icom IC-A20, proceed as follows:

1. Remove 4 screws holding back panel,
2. Remove 4 screws holding battery clip,
3. Remove battery clip and separate front and rear halves of radio
4. Remove 4 screws holding VOR unit mounted on the front panel so as to reveal Logic Unit.
5. Looking at the component side of the Logic Unit(opposite side to buttons and display), locate D711,
6. Directly above D711 You will see 3 empty pads in a triangle (SO-23 outline, this is where You need to fit a diode. The original diode used is 1SS187, but any SMD diode will do, or even a standard small wire ended diode. Solder anode to UPPER pad, and cathode to LOWER LEFT pad.
7. Reassemble the radio and reset CPU by holding Function and Clear buttons while powering up the radio.
8. Test the extended frequency range to see if mod was successful (mine was)118.000 to 136.975 MHz.

Den
 Topic: ICOM IC-V8000 Power Mod - Transistor Replacement
ICOM IC-V8000 Power Mod - Transistor Replacement [message #218] Sat, 26 December 2009 09:27
root  is currently offline root
Messages: 145
Registered: December 2004
Senior Member
After the power transistor 2SC1971 blow up Adnan Al-ZADJALI replaced it with another 2SK3075. This transistor was more available and easier to get, and at the same time it also added a little more power, from 68 to 71 watt.


[Updated on: Sat, 26 December 2009 09:30]

 Topic: Icom IC2200H FM Discriminator Lohoneyion
Icom IC2200H FM Discriminator Lohoneyion [message #187] Wed, 19 November 2008 22:43
fungkh  is currently offline fungkh
Messages: 2
Registered: September 2008
Location: Keningau
Junior Member

Hello all, someone could help me the lohoneyion of Icom IC2200H FM discriminator/SQL location on board? Thank you

[Updated on: Tue, 30 December 2008 23:41]

 Topic: IC-7200 Band Voltage Modification
IC-7200 Band Voltage Modification [message #179] Fri, 29 August 2008 21:40
root  is currently offline root
Messages: 145
Registered: December 2004
Senior Member
IC-7200 Band Voltage Modification
If you want to connect an external unit which can be controlled by the band voltatge from [ACC] connector, the modifihoneyion is necessary as in pdf attached.
The band voltage appears from pin 5 of [ACC] connector after modifihoneyion (1) is completed, or the regulated 8 V appears from pin 1 of [ACC] connector after modifihoneyion (2) is completed.

Performing this mod is the customer's responsibility. Icom does not guarantee this modifihoneyion's result.

[Updated on: Fri, 29 August 2008 21:46]

 Topic: IC-2200H MOD for extended RX/TX range
IC-2200H MOD for extended RX/TX range [message #94] Tue, 09 January 2007 23:31
root  is currently offline root
Messages: 145
Registered: December 2004
Senior Member
RX receive circuitry can be modified to receive from 118 MHz to 174 MHz. This requires the removal of a surface mount diode D 11 from the Logic Board. It is the only non SMT-Diode of the Logic Board.

TX transmit circuitry can be modified to transmit from 136 MHz to 174 MHz. This requires the removal of a surface mount diode D 13 from the Logic Board. D 13 is near by D 11.

73, 55 de Wolf, DL5DKW

Thanks to hs9dih for this schematic.
Forum: Digital Modes
 Topic: PACKRATT PK-232 Mods - Eliminate Noise
PACKRATT PK-232 Mods - Eliminate Noise [message #3039] Sun, 01 June 2014 19:22
root  is currently offline root
Messages: 145
Registered: December 2004
Senior Member
The following information was received from Wolf, ZS6AQC, concerning new Eproms for the PK-232 PAKRATT, plus a modification to eliminate noise from the op-amps. On recommendation of OM Piet, ZS6AQC I checked the noise in the power bus to the MC34074P op-amps and found (just like he said) that there is a lot of rubbish between the pins 4 and 11 of U23, 26, 28,30, 32 and 34. So, I placed some 1 microFarad caps across them and my receive noise is much less (measured on a mark=space scope cross display). In fact, I can now even copy some steady signals that don't even raise the S-meter needle. Hope you can improve yours also? This was received from OD5NG: he made this mod and results were outstanding.

Then Clark, W9CD made the modification and was pleased with the results. Consequently, I bought from Radio Shack 6 each 1 MF tantalum capacitors ("condensers" to Old Timers), and mounted them on the bottom of the board, with the shortest possible leads in the positions described above. The results are OUTSTANDING!!! RTTY signals I could not copy before are now perfect copy, even when you can barely see the traces on the scope. ARQ links, which could not be made before, now flow smoothly. The only thing I don't know if the mod will work if the latest version of the PK232 firmware upgrade is not installed, but I would think that it will. Give it a try and you will be pleasantly surprised.

P.S.: The part number for the referenced capacitors is:
Radio Shack # 272-1434, 1 MFD 35 Volts (Tantalum). Cost $ .59 each.
 Topic: Digital Mode Samples
Digital Mode Samples [message #1251] Sat, 11 February 2012 04:15
root  is currently offline root
Messages: 145
Registered: December 2004
Senior Member
KB9UKD has a great archive of digital modes and their audio files (what they sound like).

http://www.kb9ukd.com/digital/
 Topic: Packet
Packet [message #378] Sun, 22 May 2011 12:08
W2EVU  is currently offline W2EVU
Messages: 1
Registered: May 2011
Location: Sodus Point, NY
Junior Member
I am looking for a packet program that will work with Windows 7 and a Yeasu FT-897D transceiver. I would prefer a soundcard program, but a TNC program would do.


W2EVU
 Topic: PSK31 Frequencies
PSK31 Frequencies [message #18] Fri, 04 March 2005 00:40
kc2nda  is currently offline kc2nda
Messages: 29
Registered: December 2004
Location: New Paltz
Junior Member
Here is the list of frequencies I have for PSK31 so far:

2 Meters = 145.550 and 145.140
10 Meters = 28.120
15 Meters = 21.070
20 Meters = 14.070.150
30 Meters = 10.142
40 Meters = 7.035
80 Meters = 3.580


If there are any more hot spots, please post them. Thanks.


KC2NDA

[Updated on: Mon, 07 March 2005 00:54]

Forum: Arduino
 Topic: Arduino RS-232 to RS-485 Converter
Arduino RS-232 to RS-485 Converter [message #3033] Mon, 28 April 2014 22:51
root  is currently offline root
Messages: 145
Registered: December 2004
Senior Member
If you have one of these RS-232 to RS-485 converters (probably bought from E-BAY):
 Arduino rs-485 to rs-232 Converter

You will probably get a description like this:

* It is able to convert RS-232 signal to RS-485 balanced differential signal and extend the communihoneyion distance to 1.2km.
* It uses a particular pump to gain power from RS-232 signal (RTS, DTR, TXD) without initializing the RS-232 series interface.
* This interface converter does this without requiring any AC or DC power.

You will have problems with this converter from the arduino unless you read the spec sheet. Unfortunately the sellers will probably not give you the schematic or tell you how the circuit works.

I used this converter along with an arduino using the TX and RX TTL output to a MAX232 circuit, then this plugged directly into the RS-232 to RS-485 converter which in turn was connected to the power meter.

The response from the arduino was perfect. Not problems. But the power meter was not receiving the correct data.

The problem that the sellers don't tell you very clearly is what is needed to power the converter.

The trick here is to read this sentence a few times to understand it: "It uses a particular pump to gain power from RS-232 signal (RTS, DTR, TXD) without initializing the RS-232 series interface." So in order to get this RS-232 to RS-485 converter to work, you will need to hook the RS-232 serial port's DTR and RTS pins to the 5V Pin on the arduino (or another source if you have it), pin 5 of the serial port to Ground on Arduino, and the TX and RX from the Arduino to the corresponding pins 2 and 3 on the RS-232 port.

Pin 4 (DTR) - Jumper these two pins and hook to 5V from arduino
Pin 7 (RTS)

Once this is done, the RS-485 device will have enough power to send the correct data through.

*You could get around all of this by just purchasing a RS-485 plug in module for the arduino. It will save you a lot of time since these modules will convert the data for you without having to go to a TTL to RS-232 conversion, then to RS-485.
 Arduino rs-485 Converter Module

[Updated on: Tue, 13 May 2014 02:16]

Forum: Yaesu Mods
 Topic: FT-301D Display Replacement Kit
FT-301D Display Replacement Kit [message #3026] Sat, 01 March 2014 03:58
HB9GAA  is currently offline HB9GAA
Messages: 1
Registered: February 2014
Location: Switzerland
Junior Member
Hi, I developed a kit to replace the display board for the FT- 301D. No SMD were used and the kit can be assembled by a radio amateur in about an hour . The new display has, in addition to the frequency display, various advanced features. For example, the supply voltage of the FT- 301D can be measured or the band limits according IARU can be signaled. For disabled HAMs the displayed frequency and voltage is output in Morse code. With an IR remote control parameters can be changed. The software can be updated via the USB interface. A user manual is available on http://shop.elcon.ch/pd-1503415091.htm?defaultVariants=searc h0_EQ_Bausatz_AND_{EOL}&categoryId=1 . The selling price of the kit, depending on demand, is about $90 plus S&H. If you are interested, please write me to hb9gaa@arrl.net 73 de HB9GAA, Roland
 Topic: Yaesu FTM-400 DR Extended Band Mod 136-174 / 400-480MHz
Yaesu FTM-400 DR Extended Band Mod 136-174 / 400-480MHz [message #3025] Tue, 21 January 2014 01:13
root  is currently offline root
Messages: 145
Registered: December 2004
Senior Member
New frequencies after the modification:
136-174 mhz RX/TX
400-480 mhz RX/TX

1. Open the upper shell (speaker)

2. Lithium battery located on the left side

3. Identify positive symbol on lithium battery

4. Remove resistance as shown in photos

5. Perform a CPU reset (page 61)

http://www.hamradio.cc/images/forum/mods/5130_FTM-400-MOD2_thumb.JPG

http://www.hamradio.cc/images/forum/mods/5130_ftm-400-mod1_thumb.JPG

*NOTE: Mod will not work on US version

[Updated on: Tue, 21 January 2014 01:17]

 Topic: Yaesu VX-8R Mod Out of band
Yaesu VX-8R Mod Out of band [message #2995] Sat, 06 July 2013 00:13
root  is currently offline root
Messages: 145
Registered: December 2004
Senior Member
The software mod did not work at all. Then I initially cut the track leading from the resistor, without actually removing the resistor. This opened up the 1.2m band (220 Mhz, which was not available prior to cutting the track)but did not expand the other bands.

Later, I actually removed the resistor. This opened up the other bands, the 2 meter band now has a working bottom edge at 140 Mhz, everything (including ARS) works.

I suspect that the software mod would now also work, and I could change the country code as described in an earlier post, but I haven't bothered as there isn't anything in the 130 - 140 Mhz range I am currently interested in. If anyone has a similar experience and also tries changing the country code via the software mod I would be interested in hearing about the experience.

by Donna Murray
 Topic: Yaesu FT-230R Problems
Yaesu FT-230R Problems [message #2991] Thu, 20 June 2013 00:09
root  is currently offline root
Messages: 145
Registered: December 2004
Senior Member
Yaesu FT-230R Problems
NO RF OUTPUT : The PA module is a common failure on this unit.

NO RF OUTPUT WHEN HOT : PA.

NO RF OUTPUT IN THE LOW POWER POSITION : Check the PA.

RF OUTPUT INTERMITTENTLY FALLS OFF : I have seen two or three cases where the PA has intermittently gone into oscillation. In both cases this was due to internal faults within the PA module. It should be noted that this oscillation can be sufficient to blank out a nearby TV, and this fault should be suspected if there is a complaint of TVI. It should also be noted that the PA continues to oscillate and draw current when returning to receive, and EVEN IF THE FRONT PANEL POWER SWITCH IS TURNED OFF.

NO AUDIO OUTPUT : Suspect Q07 - the audio o/p IC.

MUFFLED AUDIO ON RX : Note there is an internal tone control (VR1001) on the main PCB. A lot of people don't know it's there.

OFF FREQUENCY TX AND RX : If this is only slight then align the PLL. If the error is significant then the local osc xtal should be checked.

BADLY BROKEN UP ON TX+RX : Check X03 (5.76MHz) in the PLL.

ERRATIC TUNING : Tuning step switch.

144-148MHz OPERATION : On the micro board there are spaces for four small tinned copper wire links next to each other. In normal UK versions, two links, J1 and J4 are made. Cut J1.

S-METER READING FALLS OFF AS UNIT WARMS UP : See Yaesu mod sheet.
Forum: Radio Equipment
 Topic: ForSale CHEAP PRICE RADIO Kc6wir@yahoo.com
ForSale CHEAP PRICE RADIO Kc6wir@yahoo.com [message #3022] Mon, 04 November 2013 07:06
raymtcn73  is currently offline raymtcn73
Messages: 2
Registered: November 2013
Junior Member
Flex-5000 100 Watt SDR Transceiver ...........$1550 /1175 Euro
ACOM 1000 ....................................$1600 /1215 Euro
AmeritronAL-1500 .............................$2100 /1594 Euro
QRO HF-2500DX 160-10M HF Amp .................$1600 /1215 Euro
ICOM IC-7700 .................................$2200 /1670 Euro
ICOM IC 9100 .................................$1600 /1215 Euro
Icom IC-7000 .................................$750 /569 Euro
Icom IC 775DSP ...............................$1100 /800 Euro
Icom PW-1 ....................................$1700 /1290 Euro
ICOM IC-756-Pro III ..........................$1200 /911 Euro
KENWOOD TS-2000 ..............................$900 /650 Euro
Kenwood TL-922A HF amp .......................$750 /569 Euro
Alpha 9500 ...................................$3000 /2278 Euro
Ten Tec Orion II .............................$1300 /987 Euro
Ameritron A-l 1200 ...........................$800 /607 Euro
Elecraft K2 ..................................$500 /379 Euro
Elecraft K3/100 ..............................$1850 /1404 Euro
Yaesu FTDX 9000MP ............................$5500 /4176 Euro
Yaesu FTDX 5000MP ............................$3500 /2657 Euro
Yaesu FTDX 3000MP ............................$1600 /1215 Euro
YAESU FL-7000 SOLID STATE HF LINEAR AMPLIFIER.$1000 /725 Euro
Yeasu FT-857D w/ LDG Tuner....................$620 /450 Euro
Yaesu FT920 ..................................$750 /569 Euro

I can ship worldwide.
All radios are in a perfect working condition
Kc6wir@yahoo.com
+1 8323232144.
kc6wir
Raymond.

  • Attachment: Forums.jpg
    (Size: 46.82KB, Downloaded 363 time(s))

 Topic: ADI AT600 Radios - HELP
icon9.gif  ADI AT600 Radios - HELP [message #209] Sun, 27 September 2009 15:29
RBoyette  is currently offline RBoyette
Messages: 2
Registered: September 2009
Location: Ft Myers, FL
Junior Member
Still have my old SAR radios and pulled them out after years of being put away. Still work but I need a manual or someone who knows how to program them. I also need to know where I can get new batteries for them. I am doing mounted patrol work now and would like to have these with me in case we do a recovery or event.
Any help would be greatly appreciated.


RBoyette
Forum: Rasberry Pi
 Topic: Raspberry Pi 1Wire DS18B20 Thermometer
Raspberry Pi 1Wire DS18B20 Thermometer [message #3021] Sat, 02 November 2013 22:20
kc2nda  is currently offline kc2nda
Messages: 29
Registered: December 2004
Location: New Paltz
Junior Member
I will be controlling a 12V Fan with a Raspberry Pi and a DS18B20 waterproof thermometer. The DS18B20 uses 3 wires even though they call it a 1wire system. The one wire is actually what makes the communication the other two is power and ground. I purchased the DS18B20 thermometer from ebay and they were pretty cheap. The DS18B20 thermometer was in a waterproof shell. The only problem I had which took me about 2 nights worth of playing around with the coding, the Raspberry Pi, and the 1wire DS18B20, was the wiring diagram that was on the Chinese seller's website of the DS18B20 stated that the yellow wire was ground and the green wire was the data line. This was wrong. Usually green is the common wire and I was a little skeptical at first but figured it was from China so anything is possible.

Of course, I didn't have any other 1wire devices to test on the Raspberry Pi. I couldn't test to make sure the Raspberry Pi was not functioning or the 1Wire DS18B20 was not functioning. Finally I took a chance and reversed the ground and data lines and it worked like a charm.

The 12V fan will also be controlled by the Raspberry Pi. A 555 timer will be used in conjunction with a digital potentiometer to adjust the fan speed.

Project pictures and circuit diagrams will follow.
Forum: Repairs
 Topic: Rigol DS1052E Hack to 100MHz
Rigol DS1052E Hack to 100MHz [message #1770] Wed, 02 January 2013 05:37
root  is currently offline root
Messages: 145
Registered: December 2004
Senior Member
The Rigol DS1052E 50MHz scope arrived and it has been sitting for about a year (I guess maybe it is out of the warranty now anyway, so time for the HACK!) We finally got around to hacking the 50MHz beast to 100MHz. The unit came shipped with 00.02.05 SP1 firmware. This was tricky because RIGOL knew about all of the hacking going on. They put a stop to downgrading the firmware with the 00.02.05 firmware version.

The only way to hack this unit is to downgrade it to the 00.02.02.02 firmware. This firmware allowed you to change the serial number and model number which changes the scope to 100MHz. To do this, you need to use a USB or Serial port with special commands. Any newer firmware than 00.02.02.02 supposedly removed this feature. The trick was to take the 00.02.02.02 firmware and change the header on the file to reflect a larger firmware version. RIGOL also obscured the firmware version in their new firmware (02.05) so it isn't as easy as changing the numbers intuitively. With the right combination and a hex editor, the firmware was patched to make the scope think that the firmware was newer, but in fact, it was the old 00.02.02.02 firmware! Nice hack that actually works!

Linux was not playing well with the serial port and USB port, so Windows was used to make the serial/model number changes. After wondering why Windows was only recognizing it as a hard drive, the option for "Computer" was found in the "I/O Setup" for "USB Device". Once that was changed to "Computer", Windows recognized the RIGOL unit and the numbers were able to be changed. I bet this was the only problem with Linux also. But the job is done and there is no need to go back to try Linux at this point.


I wonder if the hack actually increased their sales or lost them money due to everyone purchasing the same unit for half the price? I know the purchase of this particular unit was because it could be hacked to 100MHz so my opinion is they gained more business and publicity from it.

http://www.hamradio.cc/images/projects/rigol/RIGOL_ds1052E-Hacked.jpg

[Updated on: Thu, 03 January 2013 02:53]

 Topic: GeForce 7600 GT 1500uF 6.3V FZ71 - Bad Capacitors
GeForce 7600 GT 1500uF 6.3V FZ71 - Bad Capacitors [message #304] Wed, 10 November 2010 01:44
root  is currently offline root
Messages: 145
Registered: December 2004
Senior Member
I had the same problem many people are having with the GeForce 7600 GT video cards. I had 2 x GeForce 7600 GT cards in the same machine (...running 4 monitors...). The 1500uF capacitors are all crap. They probably cheaped out on them when manufacturing. On one card I had 2 caps blown across the inductor. But I pulled all of the 1500uF 6.3V caps on the board and tested them all. ALL of them failed their leakage test. So the best thing to do on those is to replace them all. Even if they look good, replace them. The 1000uF 16V cap tested fine. Cards work great afterwards...
Pages (6): [ «    1  2  3  4  5  6    »]


Current Time: Sat Sep 20 22:00:27 EDT 2014

Total time taken to generate the page: 0.08993 seconds
.:: Contact :: Home ::.

Powered by: FUDforum 2.7.6.
Copyright ©2001-2007 FUD Forum Bulletin Board Software