On Tue, 2010-03-09 at 18:14 +0000, AirRadio wrote: > Dilemma time... I have been offered a TR-7 but I have to sell my > C-line to make room, now, comparisons, is the TR-7 any better than the > C-line or the same, apart from the normal cosmetic issues (sticky > paint etc) am I going to gain in the rx dept, also any other faults > etc, the TR-7 seems to have a good write up etc though, but so does > the C-line. > 73 Max > As always, the correct answer is "It depends...".
But then I don't think so. TR7 hands down. TR-7 Pros: If it hasn't been done before, an hour or so's work plus a foot or so small gauge wire and some small signal diodes, turns a TR7 into a VLF to 30 MHz Rx and a 10 ham band LF transmitter. There are optional TR-7 plug-in cards creating the all-band capability and WARC band Tx, but the trace snip and diode hard wired programming is way cheaper. Crystal controlled (channelized) Rx and or Tx are possible with the plug-in card option. Assuming you run your transmitters into a matched load, the TR7 with a fan should outlast a T4XC with a fan plus it won't look like a kluge. Final amplifier vacuum tubes are consumables and their cost approaches that of the TR7 final transistors, although they are easier to replace. The Tx VSWR shutdown eliminates final tune/load capacitor breakdown when transmitting into non-50 Ohm loads. Band switching is relatively idiot-proof and quicker. However antenna switching is not idiot-proof. 8-) Built-in SWR bridge. There are fewer lethal voltages floating around the inside of the TR-7. The constant thunder storm in an un-modified R4C is distracting. Once calibrated against an external attenuator, the TR-7 becomes a piece of versatile test equipment ala a selective level meter. TR-7 Cons: You need an RV7 or equivalent for Rx/Tx split operation greater than a KHz or so. How the respective radio works is more easily understood for the C-line. Depending on your experience and competence the C-line is easier to work on. The TR-7 audio gain does not quiet the Rx audio output completely. The addition of a series resistor in the audio output line reduces this annoyance but does not eliminate it. The C-line "might" be more sensitive on 10 meters. Some of the above negative observations may be petty and at the worst, may not be true. Additionally, they not apply or be important to all TR-7 and C-line users. However, the above has been my experience. Joe, K9HDE PS At a significant expense, the R4C can be modified into a world class CW Rx but if this is news to you, you wouldn't make the mod anyway. _______________________________________________ Drakelist mailing list [email protected] http://mailman.zerobeat.net/mailman/listinfo/drakelist
