[Elecraft] low tune power with SSB module

[Chris]

Hello,

I posted a couple of days ago regarding a strange problem I had with low 
power output when testing my KPA100. Well I soon discovered that the low 
power was due to low drive from the K2.

Whilst investigating this I removed the SSB to access U10 etc., inserted 
the links and the cap. Pressed Tune to investigate and my power was back 
to normal. Re installed the SSB module and Power is down again.

The symtoms are that I can get about 2W on 40m rolling of to a 100mW, or 
so, on 10m.

Mike, VP8NO, lent me his spare SSB module and that gives full power on 
tune. His had firmware 1.07 mine is 1.08.

I started checking voltages around my module and discovered that you 
have to press PTT to get the Tx readings that are listed in the voltage 
table in the manual (it doesn't specifically tell you that so I thought 
that Tune would do!). Whilst doing this I discovered that SSB is 
delivering full power so it is only in tune mode that power is being 
limited.

What exactly does tune do that interacts with the SSB module?

I read somewhere, in the archives for this list I think, that tune power 
may be limited to 2W by some SSB firmware versions. Is that correct?

If there is a 2W limit on tune (20W I guess with KPA) what would be 
causing this 2W to roll off to almost nothing at 10m?

Without the SSB module installed I can get good power on all bands. With 
the SSB module installed and using the whistle test I can get good power 
on all bands. So it's definitly only the tune mode that is affected.

Tune power override, doesn't make any difference.

I'm still using a manual ATU and I need a bit more juice to able to get 
a good indication on my meter!

The good news from this is that there is nothing wrong with my KPA100 :-)

Cheers
Chris VP8BKF