I want to thank everybody for the wonderful comments, it has been most
instructive. Although much of the technical parts were over my head ((for the
moment anyway)) it reinforced what I instinctively knew.
Only use enough power to get out, not overdrive the sound card, not use my
radio fix dinner on, and finally #1 use an external sound board and not the
laptops internal sound card. I suspect that is 90% of my issues. When I was
using my Linux box (it has two sound cards, an onboard and an external Sound
Blaster) I was getting good reports, it has only been since using the laptop
that I have no joy. This however is a discussion left for another day.
Hint: fldigi by itself good, fldigi and xlog or similar application together
not good.
Once again I want to express my appreciation to the community for their help.
- 73
Ralph (AJ4GR)
--- In digitalradio@yahoogroups.com, "Toby Burnett" <ruff...@...> wrote:
>
> I agree, Surely this chap has seen the power meter going up and down with
> his voice.
> It's pretty obvious that there is a big difference between running ssb and
> 100%modes like psk
> If you have a built in amp meter on your rig like my IC 720A you will see
> that your amp draw
> Fluctuates a lot in ssb and not in PSk etc. Big AMPS Big HEAT !!!
>
> I used to have a little old fm 2m handie that was my only 2m rig. Used to
> actually burn my hand after a half hour rag chew lol.
>
> Please just think about the current draw and heat and you will quickly see
> why we reduce power for digi modes.
>
> Of course if you have a 1kw amp then go right ahead lol but it is amazing
> what you can do with a few watts on digi modes and of course CW (the
> ultimate digi mode )
>
> Please don't use your radio to toast bread.
>
> Toby
>
> PS I run every mode with no ALC. Never had a problem.
>
> -------Original Message-------
>
> From: bruce mallon
> Date: 14/07/2009 11:49:02
> To: digitalradio@yahoogroups.com
> Subject: Re: [digitalradio] Digital modes and old husband's tales
>
>
>
>
> 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...@...> wrote:
>
>
> From: David <djm...@...>
> 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
> >
> >
>
