You may need to check your internal grounds, including all screws and any copper fingers attached to boards. As well, the board cage covers need to be attached with all screws, snug but not over tightened. But first add the ground strap to the high pass filter module as shown in the attached photo. This will help with stability.
Also check the predriver gain adjustment pot. In a healthy TR7 with the ALC adjustment set for 150 Watts on 20 Meters you should get close to 100 Watts on 10 and 15. This is normal. The ALC and predriver gain adjustments work together and if mis-adjusted can cause issues.
You may also want to test the PIN diodes. Procedures are posted on the internet and in this group.
On Mon, 03 Feb 2025 08:53:27 -0800
"Michael Jensen via groups.io" <kavigal@...> wrote:
Hardly been using it for TX until recently, then I notice that on 10 Meter output is close to 2.5 watts..
Okay, not much.. On 15 meters the current draw is close to 31 amps to produce 100watts! Quite a bit.
more reasonably 21-22 amps on other bands.
So went for an TX alignment, if I crank up the pre drive I can get it up to ~60 watts on 10 meter
obviously not a good scenario and the dr7 board definitely does not like it as the display starts to be all over the place during TX,
with pre drive fully cranked up 40 Meters the PA self oscillates, not good.
So my thoughts, something in the pre drive section or bandpass maybe?
Looking for any suggestions before going nuts down that route.
Thanks on advance!
Best Regards, Michael - oz8abr
--
73
-Jim
NU0C
Jim Shorney
