PD0LQQ - TRX Bench

Login Formulier

Article Index

TRX Bench

Götting HG70D 2M FM-SSB-AM transceiver repair

This 50 year old transceiver had no power output.
There were several reasons for this.
First, all foil trimmers in the PA were fried...., the needed to be replaced.
It also turned out that a 10 ohm 5 Watt resistor became 8 Kohm...
It also turned out that no 24V was present on the PA so I checked the 2N3055,
this is the switching transistor and voltage regulator for the PA supply voltage.
The 2N3055 turned out to be defective, the transistor that switches the 2N3055 at
TX the BC140-16 was also defective.
All parts replaced and now the set works again!

Click here to see the fotoalbum of the Götting HG70D repair

CliCK BELOW FOR THE REPAIR OF THE HG70D ON YOUTUBE

Götting HG70C 2M FM-SSB-AM transceiver

A quick look inside the Götting HG70C.
This is the C version, so with 2 tubes in the PA.

Click here to see the fotoalbum of the Götting HG70C

Yaesu FT736R repairs.

I've had 3 Yaesu FT736r's on the measurement table.
I adjusted all 3 according the service manual.

First repair:
In one I had to repair the power supply. This is a major problem with this device, the electrolytic capacitors all need to be renewed to bring them back to life.
It is also best to replace the power resistor for a larger wattage. I also renewed the S meter lighting.
Because there is no ctcss encoder as standard, I bought a kit and made it myself and placed it in the transceiver.

Click here to see the fotoalbum of the repairs from the yaesu FT736R

Click here for the service manual from the Yaesu FT736R

Second repair:
The second repair was more a modification....
I had bought a 2nd hand 736. When it came in and unpacked it, I felt and heard that there was something loose in it. Before I plugged it in, I thought it was wise to open it to see what was wrong. What I saw was AMAZING! ... I saw that the original power supply was no longer in it, and an external power supply was stuck in it instead ... the case of that external power supply had been removed to fit the case of the 736 .... That was loose and the noise caused was the fan that had come loose during transport ... I had never seen this solution (HI) I took out the entire power supply (and turned it back into an external power supply) The 736 was brought back to its original condition without a power supply. This eventually worked on external 13.8 volts.
Of course the seller didn't know anything ... He could have bought it like that himself ... I don't want to rule that out.

Third repair

Unfortunately, the processor board of this transceiver was defective and unfortunately there is no new processor available, not even 2nd hand. The transceiver kept on transmitting... and there was no way to put it in receive.... something must have gone wrong connecting an external power amplifier. Via the PTT there must have been voltage on the processor ... unfortunately this is not secured and therefore the processor has probably become defective.



                                          The FT736 in action on Youtube

Yaesu FT101ZD "killer cap"

This Yaesu FT101ZD (MK3 version) was purchased new by my
father in the early 80's.
This transceiver has made very few connections in its
life.... The last 30 years this TRX has not been in use.
I got this from my father, and had to do maintenance service.First I had to clean all potentiometers and all switches,

Yaesu FT101ZD top view

for this I used PCC cleaner, DO NOT USE CONTACT CLEANER!!
Then I replace the "killer condenser" if it fails, the full
300 volts will be applied to the grid of the 2nd power tube in the PA.
This causes the power supply transformer to draw all the current
it can supply....result?....a defective power supply transformer
and defective finals.....you then have a demolition set. It is
therefore important to renew this capacitor in advance.
Normally the original is a 1KV version, when replacing it is better
to have one of 3KV.

Click here to see the fotoalbum of the replacing the "killer cap"

Click here for the service manual of the Yaesu FT101ZD

The old "Killer cap"

The location of this capacitor is under the PCB board where the 2 PA tubes are located

The new cap (3KV)

Please see the column Yaesu FT277ZD! (this is the same transceiver as the Yaesu FT101ZD)
Here you can see a Youtube film from the repair, servive and replament from the "killer cap"

Sommerkamp FT277ZD

This is the same transceiver as the Yaesu FT277ZD.

Sommerkamp FT277ZD (Yaesu FT101ZD) HF transceiver service
Not all service is filmed.....
Problems: Antenuation switch bad.
Drive potentiometer works bad.
Power indication on meter not working.
"KILLER"condensor replace.
Relais must have service.
Various loose contacts.
Regular service.

Service of the Sommerkamp FT277ZD on Youtube

Uniden 2020 HF transceiver

Click here to see the fotoalbum of the repair from the Uniden 2020

Click here for the manual of the Uniden 20202

Uniden 2020 repair and cleaning on Youtube

Icom IC-R7000

Icom IC R-7000 repair and alignments.
Problems: off frequency, sensitivity, light S meter, backup battery, and casing.

Click here to see the fotoalbum of the repair from the Icom IC-R7000

Click here to see the service manual from the Icom IC-R7000

Icom IC-R7000 repair on Youtube

Kenwood R1000

kenwood R1000 problems:
No 200 Khz-2 Mhz receive because static discharge in the first HF stage.
Few components are burned out.
No display because defective Q34 No meter and VFO light.
Power supply recap Some alignments.

Click here to see the fotoalbum of the repair from the Kenwood R1000 (display replacement)

Click here for the service manual from the Kenwood R1000

Kenwood R1000 repair on Youtube

Kenwood R1000 repair on Youtube (display replacement this because defective Q34)

Apple ipad air 2 battery replacement

Apple ipad air2 battery replacement on Youtube

Daimond GZV4000

Daimond GZV4000 power supply repair on Youtube

Philips 22RH521

Problems:
1 Left VU meter does not work.
2 service all switches.
3 service all potentiometers.
4 Adjustments idle current power transistors.
5 PU one channal does not work.

Philips 22RH521 repair on Youtube