SO I have searched and searched, what is the adjustment for RV1 please.

--
Frank, KG9H

Frank,
As far as I know, there is not an official way to adjust RV1.? It is a drive setting that I have used to set the output of the PA to a value that is about 12 Watts on 80 meters in CW mode with 13.8 volts supplied.? I have not tried to push the finals beyond that point with 13.8 volts.? Even so, RV1 tends to be close to the maximum level (fully counter-clockwise) to get that value. It seems that it was more a way to reduce power than adjusting to a point where later stages are overdriven.?

One of these days I will get around to measuring the effect on output purity.? So far have not had any issues with the above setting process.? I have tested my rigs for harmonic and spurious.? I have not tested for linearity other than from signal reports and monitoring with my other rigs.

73
Evan
AC9TU

When driving my little XDT-PA70 linear amp I use RV1 to keep the amp input below 5 W. I turn it up when not using the amp. Same as Evan I have not noticed reduced output purity?
--
?

73
Mick VA3EPM?

开云体育

Hi Frank nice to see you on here, like others said it is for adjusting the drive level for the amplifier chain. I have adjusted it in CW mode starting at a lower drive and increase it until there is no increase in output or to the level I want on 40mtr band. It works for me.?

Skip hi and good day. ?Nice to hear from you.
Yes I tried that for CW and it adjusted fine. ?I did not see a decrease in SSB though which prompted by question.

Will look you up on QRZ.

Stay safe.

--
Frank, KG9H

Thanks Mick I will be looking for spectrum purity later this week. ?Too many irons in the fire right now.

Stay safe
--
Frank, KG9H

Evan, thanks.
I went back to V3 and V4 and did not see any references to it. ?Although I was looking for power (CW adjusted fine and I adjusted to 10 watts) I did not think of spectral purity. ?It will take a few minutes to set that set-up here but will do that later this week.

Thanks again Evan.

--
Frank, KG9H