And here are some things to read about K2+XV144! I think something went wrong with measured K2 or XV144 but this are the results and Henning comments:
http://www.df9ic.de/tech/trxtest/trxtest.html Some comments from Eric, Wayne or others is Wellcome! S55M Adi ----- Original Message ----- From: "Ken G3WCS" <[EMAIL PROTECTED]> To: <Elecraft@mailman.qth.net> Sent: Saturday, April 09, 2005 12:33 PM Subject: [Elecraft] Elecraft XV144 and XV50 - TX Noise and birdie > Hello all, > > A few months back I put together the XV144 and XV50 transverters. Both > work fine but following some comments from very local stations I decided > to make one or two checks. > > I am comparing these tranverters with my own original 144Mhz transverter > which I built about 15 years ago. > > With no input to either transverter but with the input terminated at 50 > ohm and with a resonant antenna connected, listening on another receiver > with an antenna connected reveals quite a high hiss or mixing noise when > the PTT line is operated. This happens on both the 50 and 144 Mhz > transverters. If I operate the PTT line of my old home brew transverter > there is no such noise or if any it is very much reduced. I am sure the > hiss (phase/mixer noise) is many db down on the normal output level but > it is nevertheless much greater than my original home made unit. > > Secondly, and somewhat more worrying is a drifting birdie that both the > XV50 and the XV144 produce. Once again I know these are many db down on > the normal output but the 144 Mhz birdie is of sufficient strength that > a station 15 miles away heard it whilst trying to work an EME QSO. It > drifted across the frequency he was using. On my particular transverters > these birdies occur at about 50.130 Mhz on the XV50 and about 144.140 > Mhz. They seem to drift LF during TX and at a rate of about 10 Khz in 5 > minutes. > > I wonder if anyone else has made any observations and come up with a > cure. I all other aspects the transverters are excellent and totally > stable. Indeed, the 144 Mhz version is fitted with a crystal oven. > > I know there was a thread on here a month or two back regarding phase > noise being heard by stations within a 20 Km radius during high levels > of 144 Mhz activity. > > Has anyone else got any more comments or observations to make. I know > that my observations are not exactly 'scientific' but there are made by > comparison with a different transverter which does not exhibit these > problems. During all these tests the transverters have had their inputs > and outputs correctly terminated with no 28 Mhz drive source connected. > > Sorry for the long waffle. Any comments most welcome. > > > Best 73, > > > Ken G3WCS. > -- > > Ken G3WCS > IO83rh : Cheshire : NW England > (+44) (0)870 765 1632 (home) > (+44) (0)7733 400 950 (mobile & sms) > > _______________________________________________ > Elecraft mailing list > Post to: Elecraft@mailman.qth.net > You must be a subscriber to post to the list. > Subscriber Info (Addr. Change, sub, unsub etc.): > http://mailman.qth.net/mailman/listinfo/elecraft > > Help: http://mailman.qth.net/subscribers.htm > Elecraft web page: http://www.elecraft.com _______________________________________________ Elecraft mailing list Post to: Elecraft@mailman.qth.net You must be a subscriber to post to the list. Subscriber Info (Addr. Change, sub, unsub etc.): http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/subscribers.htm Elecraft web page: http://www.elecraft.com
