LOGIC TELLS YOU ..... 100 watts SSB is 25 watts FM/PSK and other 100% modes ....
Unless you like changing finals...
--- On Tue, 7/14/09, David <djm...@bigpond.com> wrote:
From: David <djm...@bigpond.com>
Subject: Re: [digitalradio] Digital modes and old husband's tales
To: digitalradio@yahoogroups.com
Date: Tuesday, July 14, 2009, 6:43 AM
Hi Andy...Ill add a quote from the Instruction Manual for the Kenwood TS140S
"While 100 watt transmissions are possible when using short duration
modes such as PACKET continued operation over a long period of time
might cause overheating. We recommend that you reduce the transmitter
power output to 50 watts whenever using one of these modes i.e
PACKET, AMTOR, RTTY, this is easily acomplished thry the use of the
front panel PWR control"
on my homebrew interface i have a pot that i use to set the drive to the
TX so that i read approx 50 watts on the Revex Power meter on the
antenna output.....
was using 65 watts one night on PSK and was told that my signal was
drifting a bit.....the internal fan didnt come on but the heatsink was
awfully warm....have since put 2 computer p/s fans on top of the
heatsink at it runs cooler and no drift on tx....
ok thats my dimes worth hi hi
73 David VK4BDJ
Andrew O'Brien wrote:
>
>
>
> The replies to Ralph's question about audio levels appear to be sound
> advice and certainly in keeping with what has been advised since sound
> card digital modes burst upon the scene. I wonder how accurate it is
> though? I have seen a few serious hams argue that "no ALC" is not
> really the case, that some ALC can be OK. I have also seen mention
> that the no ALC issue applies to some modes (like PSK) but not to
> others like (JT65A). I also wonder about the half-power advice that
> some advise. With my homebrewed interface, I could never get much
> above 40 watts before some ALC began to show. When I switched to a
> commerical interface with good isolation (Microkeyer by Microham) I
> can almost always get 100 watts output without any ALC action. I have
> not received any negative reports about my signal . If I run 100
> watts SSB for phone contacts, why would I not want to do the same for
> digital modes assuming the signal was "clean" ? . Yes, I would agree
> I should not run 100 watts if communication was possible with less
> power, but I don't think a brief PSK CQ at 100 watts is going to do
> much more harm to my finals than a 3 minute ragchew at 50 watts, phone
> . Right ?
>
> Comments ?
>
>
>
> --
> Andy K3UK
>
>
