Rick, I do not believe it makes much difference whether the rigs not in use are turned on or off. Any damage would occur in the preamp or mixer stages in most cases, and the devices are sitting there with their inputs connected whether power is on or off, but there also may be some T/R switching arrangement in a transceiver ahead of the receiver front end devices - it would be difficult to predict just how the unbiased diodes (power off) would respond if the signal were large enough - it would depend on the design. We do know that the K2 will tolerate 0.14 Vrms of input signal without damage - that is the signal level that is used for Receive Signal Tracing if one is to match the RF Probe values listed as 'expected'. I also know that my K2 will stand a 1 volt input signal without damage (that has happened several times) - but I don't know what the upper limit is and don't want to try a destructive test.
So, the real answer is either "it all depends" or "I don't know". 73, Don W3FPR Rick Dettinger wrote: > Don, > > Does it matter if the rigs not in use are turned off? I assumed that > they would have more immunity to overload if the unused rig was not > turned on. The Alpha Delta instructions says the switches are meant > to be used for switching multi antennas and one rig or multi > receivers. They do not mention multi transceivers. I use two > transceivers with one antenna but I removed the protection plug > (Arcplug) as I wasn't sure if that was the reason they didn't > recommend the switch for multi transceivers. But I always leave the > unused rig turned off. No problem so far but I only run 100 watts > maximum. > > 73 > Rick Dettinger K7MW > > > On Mar 5, 2009, at 5:52 AM, Don Wilhelm wrote: > > >> Greg, >> >> Theory says you should not have any problem. With 60 dB isolation and >> 1000 watts, there may be as much as 1 mW at the input of each >> receiver - >> that is 223.6 mV, which is a large signal, but still within the power >> handling capability of most receivers. >> >> In the practical world, if there are any leakage paths *around* the >> switch or coupling between the coax lines, then even though the switch >> itself provides 60 dB isolation, the system isolation may be much >> lower >> - just how much depends on your setup. >> >> You could set it up and test at lower power - tune the other radios to >> the transmit frequency and see what the S-meters tell you. >> >> 73, >> Don W3FPR >> >> > ______________________________________________________________ > Elecraft mailing list > Home: http://mailman.qth.net/mailman/listinfo/elecraft > Help: http://mailman.qth.net/mmfaq.htm > Post: mailto:Elecraft@mailman.qth.net > > This list hosted by: http://www.qsl.net > Please help support this email list: http://www.qsl.net/donate.html > ------------------------------------------------------------------------ > > > No virus found in this incoming message. > Checked by AVG - www.avg.com > Version: 8.0.237 / Virus Database: 270.11.8/1985 - Release Date: 03/05/09 > 07:54:00 > > ______________________________________________________________ Elecraft mailing list Home: http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/mmfaq.htm Post: mailto:Elecraft@mailman.qth.net This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html
