Title: Reviews of TCS Transmitter Post by: W1EUJ on May 06, 2006, 05:13:52 PM I have been seeking a transmitter to pair with my RAS reciever, and the TCS-12 looks very nice. I have access to a transmitter (just that, no other components).
I would be interested in hearing from TCS users about the ease of use of the transmitter, the vfo stability, the audio quality, and the use of non-oem power supplies (such as Heathkit, etc.). Thanks David Goncalves W1EUJ Title: Re: Reviews of TCS Transmitter Post by: W1EUJ on May 10, 2006, 10:07:22 AM Thanks to N3IBX and WU2D for the info and parts!
David Goncalves W1EUJ Title: Re: Reviews of TCS Transmitter Post by: Carl WA1KPD on May 10, 2006, 11:21:16 AM I have one in the long triage line. Back in the late 60s I ran one as my primary station on 160 - when nobody but W1BB was there! I also used it on 75 Am and 40 CW. I had the full boat with PS rcvr and interconnecting cables, remote speaker, and ant. coupler. I set it up so it would run both 1625s in AM mode- the stock circuit cuts one of them out. Be aware, that out of resonance, you will pin the plate meter in that configuration. The PS can be pretty simple as I recall it needs something like 200VDC/400VDC and 12 v I also put a 12AX7 speech amp in front of the mod xfrmr and ran my mike directly into that then into the mod xfrmr. I am a little bit cloudy on the details but as I recall I just grabbed a stock speech amp circuit out of the Handbook. Good luck Title: Re: Reviews of TCS Transmitter Post by: W9LBB on May 10, 2006, 01:52:19 PM I have been seeking a transmitter to pair with my RAS reciever, and the TCS-12 looks very nice. I have access to a transmitter (just that, no other components). I would be interested in hearing from TCS users about the ease of use of the transmitter, the vfo stability, the audio quality, and the use of non-oem power supplies (such as Heathkit, etc.). Thanks David Goncalves W1EUJ Hello Dave! Been running a TCS outfit here for some time now, pretty much as Uncle Sam meant it to be run, except for a homebrewed AC supply, and some selected (reversable) mods. First off, a warning... RESPECT THE RECEIVER PLATE VOLTAGE SPECS! It calls for about 200 VDC, and the supply I built runs about 275 - 300. That caused a premature failure of the RF gain control... and since the AGC switch is on it, in an unconventional setup, it is a ROYAL pain in the butt to find a suitable replacement! As has been already pointed out, in stock configuration only one of the PA tubes is used on AM (they don't light the filament in the second tube). A couple of minor wiring changes kept BOTH tubes lit in AM position, providing a good bit more output power and PA plate dissapation capability... but that exacerbated a common TCS transmitter problem. As you've no doubt already learned, the speech amp in the rig is minimalist, to the point of the rig not HAVING a speech amp! With one PA lit, the modulation is poor, not even able to hit 100%; with BOTH tubes hitting it, modulation percentages are a joke! I do NOT want to hack up the rig too badly, and everything I do has to be reversable. I haven't used the transmitter too much lately, but I think I've found a suitable answer to the mod problem. I came into a neat little plug in module made by Op Amp Labs; it's about a 2 watt audio amplifier that will feed a low impedance (like the primary of the carbon mike to 1625 grid transformer used in the TCS). It can be run off of the DC supply used to power the relays in the TCS. A second Op Amp Labs module can be set up as a mike amplifier to drive this stage; depending on the input it can use either the traditional T-17 carbon mike (ugh!), or a dynamic mike. These modules are in octal cans, and can probably be mounted inside of the rig without too much trouble. On the transmitter I cheated on the plate supply; instead of 400 VDC my supply cranks out 540 VDC under load. That extra PA and modulator plate voltage, along with both PA tubes lit, makes for a VERY meaningful increase in transmitter power output, and the transmitter doesn't seem to object any. In CW operation... the note and keying are EXCELLENT on 160 and 80 meters. On 40, things begin to get a bit chirpy, but still not too bad. The first time I used the rig on 30 meters, my CQ was answered by a Cuban, and a lot of those guys are notorious for BAD notes on CW. When a Cuban complains about your clicks and chirp, it's DEFINITELY time to look into it! <<grin>> All in all, a TCS is a pretty good rig. Have fun with it. 73's, Mr. T., W9LBB Title: Re: Reviews of TCS Transmitter Post by: Carl WA1KPD on May 10, 2006, 03:15:46 PM I do NOT want to hack up the rig too badly, and everything I do has to be reversable. I was able to locate the speach amp tube on an aluminum plate in front of the mod transformer where those huge crystals were located. So "no harm and no foul". I used the existing mike/key connector with a crystal mike and the gain control was located inside on the plate. Title: Re: Reviews of TCS Transmitter Post by: W1EUJ on May 10, 2006, 03:53:40 PM A 2W amp running off of the relay supply. I like that.
Now, does anybody have a copy of a schematic for the TCS transmitter I could borrow, or do they all come from Fair Radio Sales? David Goncalves W1EUJ Title: Re: Reviews of TCS Transmitter Post by: Carl WA1KPD on May 10, 2006, 05:25:44 PM I can PDF you one if you send me your email AMfone - Dedicated to Amplitude Modulation on the Amateur Radio Bands
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