[Amps] Problem with AL-80A

[Kari Lehtimäki]

Hi all,

Just purchased an old AL-80A and noticed that there is something peculiar going on.

I was running RTTY on 15m (300W out) and the output power started to decrease to 200W after every CQ.

So I went through all the bands from 20 to 10 and noticed the following.

Band drive Ip Pout
20m 15W 150mA 200W
17m 20W 220mA 200W
15m 25W 250mA 200W
12m 40W 340mA 200W
10m 15W 200ma 200W

What can you tell me about these figures? Is there a problem here? Has the Plate Rf Choke become resonant close on the 24.5 MHz band for some reason?

My test setup was:
FT-1000MP (Using the tuner with the amp)
AL-80A
R-7 Vertical
Bird 43 wattmeter (after the Amp. - drive power as indicated by the rig)

73 de Kari, OH2XX