"Al Parker" <[EMAIL PROTECTED]> made an utterance to the drakelist gang ---------------------------------------------------------------------- try to tell all that to those xxxxxs that camp on 14.295 +- 4kc all day & nite. 73, Al, W8UT certified grouch
----- Original Message ----- From: "don" <[EMAIL PROTECTED]> To: "Craig Roberts" <[EMAIL PROTECTED]>; "drake" <[email protected]> Sent: Monday, December 12, 2005 5:51 PM Subject: Re: [drakelist] TR-7 transmit audio saga > > "don" <[EMAIL PROTECTED]> made an utterance to the drakelist gang > ---------------------------------------------------------------------- > I think a lot of people do not realize how important it is for the ALC > to be set correctly, or even on the conservative side. While a scope will > show flat topping, they don't show bandspread very well, and few of us can > afford a good spectrum analyzer to really see what's going on. With that > being the case I have seen many hams brag about how strong their rig is, > when in fact the ALC is set too far and that extra 50watts is just going > towards splatter. I would rather operate at 90-95 watts and know that I have > a good clean understandable signal, than be at 100-120 and have to repeat > everything I say. If I really need the extra power, 10 or 20 watts probably > will not make difference, that's when the amp comes into play!! > This just shows how very important it is to have good quality, > calibrated, test equipment on hand when performing repairs or alignments. > and even then, double check! does the reading on the watt meter match with > your scope?, is that old dummy load still 50 ohms?, how about the coax > jumpers? just how old are they anyway?? so often there is thousands of > dollars in radios, and yet the $5 jumper is garbage. or the 100 watt dummy > load has regular been subjected to 150+ watts for extended time. or we > expect accurate readings from the 30-40 year old meter we bought off > e-bay!!! > > Having recently had similar issues, I have been aggressively > "remodeling" my radio/work bench. all new jumpers made, fresh coax and > connectors to the antennas, new and better quality antenna switches, new > transmatch(currently homebrewing), oscope, dvm, cap meter, and new wattmeter > next month, and even reworking the shack's ground system. > > Thanks for the update !! > > 73 Don Ke7ffm > > > > ----- Original Message ----- > > From: "Craig Roberts" <[EMAIL PROTECTED]> > To: "drake" <[email protected]> > Sent: Monday, December 12, 2005 8:58 AM > Subject: [drakelist] TR-7 transmit audio saga > > > > > > Craig Roberts <[EMAIL PROTECTED]> made an utterance to the drakelist > > gang > > ---------------------------------------------------------------------- > > As you may recall, I was complaining recently of RF contamination of my > > TR-7's transmitted audio. The problem was traced to my "aftermarket" PTT > > footswitch with unshielded leads. Removal of the footswitch cleaned up > > the audio considerably -- but not entirely. I was still getting reports > > of minor distortion. Some said I still had a little RF in my signal. > > Others described a quality that sounded like clipping. > > Then I remembered that I had installed a one-resistor mod on the ALC board > > that tightened up the decay time. Could this be the problem? > > > > I clipped out the added resistor. > > I also re-aligned the transmitter section using a newly calibrated Bird 43 > > wattmeter and learned -- to my surprise -- that the old military surplus > > wattmeter I had used to align the transmitter a few weeks ago was reading > > almost 30 watts low. Therefore, my original transmitter power output and > > ALC settings were based on a real power output of over 150 watts on 20 > > meters, rather than the recommended 120 watts or so. (My TR-7 had arrived > > at my door tweaked to put out over 200 watts and exhibited all kinds of > > weirdnesses, so even my first, faulty re-alignment had been an > > improvement). > > > > Anyway, re-aligning the transmitter with the correct, lower power output > > and appropriate ALC setting cleaned up the audio completely and I'm now > > getting reports of excellent, "broadcast quality" transmissions with a > > Heil Classic mike. > > > > I really don't know if the now-removed ALC mod was contributing to the > > problem or not -- but I think I'll just leave well enough alone. > > > > Apparently it is my mission in life to screw up so you don't have to. > > > > 73, > > > > Craig > > W3CRR > > ---------------------------------------------------------------------- > Submissions: [email protected] > Unsubscribe: [EMAIL PROTECTED] - unsubscribe drakelist in body > Hopelessly Lost: [EMAIL PROTECTED] - help in body of message > Zerobeat Web Page: www.zerobeat.net - sponsored by www.tlchost.net > ---------------------------------------------------------------------- > ---------------------------------------------------------------------- Submissions: [email protected] Unsubscribe: [EMAIL PROTECTED] - unsubscribe drakelist in body Hopelessly Lost: [EMAIL PROTECTED] - help in body of message Zerobeat Web Page: www.zerobeat.net - sponsored by www.tlchost.net ----------------------------------------------------------------------
