Re: struggling with gMFSK setup

[Harry Popov <lz1bb@mail.bg>]

Haines,

> The FT-817 manual says nothing about limiting power for digital
> modes. So apparently it's safe to run a full 5-watts, but based on
> what you say about IMD, 2.5 would be a good idea.

All said befor is corect in principe. Particularly for FT817 do not wory
so much for IMD and thermal problems. Just have in mind the radio is
prepared for FM chatters on VHF. If it is engeniered to survive 5W FM
carier it should do on PSK too.

I use FT817 for several years on digi modes HF and WSJT VHF. I worked
DXCC on all bands except 80m with 5W and 20m LW just about 5 meters
above ground. Here is how I adjust PSK31 level. I turn down audio from
sound card. Go on TX and encrease gradually until I have full 5W. There
is a point where more encrease of audio do not produce more power. That
is so called "point of compression". You should always be just on it or
strace down. IMD is good due to good ALC of transmit unit of FT817.
Later if I need QRP down I just use FT817's own power levels without
touching any more the audio level from sound card. At least I tune in
this way. I never had splatter complains. And I have several neighbours
just about 200 to 800m away from me.

According mith that PSK31 does not need power. The explanation is only
one. Majority of stations use between 10 and 30W and our 5W QRP is
compeating very well with other stations. It should be the same on CW
and almost the same on SSB if all used the minimum necessary power. You
know reality is much different. Every one and his brother use QRO and
that is only problem for QRP stations to compeat during pile ups. But
not impossible!!! While using QRP one gain knoledge and one day take the
pleasure when overshout all the QRO gung. That is real pleasure. Beleave
me I had it many many times.

Excuse my spare English. I think you got the point.

73, Harry LZ1BB