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IC-7000 different Power at different band

 

Hello all,
Greetings. This is my first post in this group. Last time when I fixed my IC-7000 I took help from the IC-7000 Yahoo group ;) back in 2009.
After almost 12 years I brought this radio out of the storage for some VHF/UHF qso. Now I found there is no power at 70cm, and HF power varies band to band.

Initial check found the UHF PA gone, bias was dropping too low. Replaced the RD60HUF1, set the driver and PA bias. Getting only around 15-20watt. 2m the PA looks ok but getting around 15W.

I have cleaned all the connectors, replaced all the flex ribbons. still no luck. The output in HF band fluctuates randomly.
Driver board no burn, put back with heat paste (old version - no resistor at gate).

I have checked all related post in this group. The BIAS of pre-driver Q101 and Q102 both ok (around 2.x V, no broken trace). Took some measurement with a cheap USB scope:

Attached is the schematic where I measured the data, and also the data table.

Can you please advise what might be the problem, or what should I check?

Thanks in advance, Fazlay S21RC

test_data.png
test_point.png

 

Silly but have you tested the dummy load is it still 50ohm on all bands being used on,
Dave 2E0DMB


On Sun, 6 Apr 2025, 20:22 fazlay.rabby via , <fazlay.rabby=[email protected]> wrote:
Hello all,
Greetings. This is my first post in this group. Last time when I fixed my IC-7000 I took help from the IC-7000 Yahoo group ;) back in 2009.
After almost 12 years I brought this radio out of the storage for some VHF/UHF qso. Now I found there is no power at 70cm, and HF power varies band to band.

Initial check found the UHF PA gone, bias was dropping too low. Replaced the RD60HUF1, set the driver and PA bias. Getting only around 15-20watt. 2m the PA looks ok but getting around 15W.

I have cleaned all the connectors, replaced all the flex ribbons. still no luck. The output in HF band fluctuates randomly.
Driver board no burn, put back with heat paste (old version - no resistor at gate).

I have checked all related post in this group. The BIAS of pre-driver Q101 and Q102 both ok (around 2.x V, no broken trace). Took some measurement with a cheap USB scope:

Attached is the schematic where I measured the data, and also the data table.

Can you please advise what might be the problem, or what should I check?

Thanks in advance, Fazlay S21RC
 

Hi Dave,
Thanks for reply. Dummy load is ok (I use the same one for my SSPA testing, and also 7300 shows ok). I have done some more measurements, specifically on J101, Driver IN and Driver OUT (attached). I have also found a reference in the group regarding voltage level of a working IC-7000 (also attached for reference.)

The power out is not consistent, sometime changes a bit.

Thanks, Fazlay S21RC

test_data_2.png
7K TX RF Levels 3.pdf
7K TX RF Levels 3.pdf

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