I guess that’s the electronic equivalent of blowing through a tube to clear the blockage. :)
On Mon, Sep 17, 2018 at 01:44 Frederick Dwight <[email protected]> wrote: > Scott, > The problem you describe is actually quite common in electronics. In > the telephone industry, especially in the “good old days” with wire cables, > sometimes with many splices it was common to get drop outs. These could be > due to a splice, wire wrap connection, oxidized relay contact or whatever, > especially with only low level signals. If the circuit also had a DC > voltage on it, the problem often did not exist. In fact it was common on > critical circuits for the FAA or military, or whatever to sometimes just > put “sealing current” on certain circuits just to be sure it was reliable. > Often we used 24 volts DC or less with only a few ma of current. At one > time I had many phased verticals which were controlled by many relays. > Occasionally the received signal would drop by many S units. Sending a > single dot, even with QRP or QRPP power always cleared the problem, > sometimes for weeks or months. So it could be a connection in the antenna > system, a plug on a circuit board, or even a relay. I have never > experienced trouble with Elecraft relays personally. Sometimes PL-259 > center pins are not correctly soldered, and can present similar symptoms. > You could try a random wire, or even something like an 80 meter dipole on > 30 meters, just to see if it was anywhere in the antenna system. Even a > volt or two is often enough to punch through a poor solder or oxidized > connection, but even something like a 0 dBm signal is just not enough. I > have identified problems with BNC connectors and adaptors purchased at ham > flea markets which are just not reliable and are probably factory rejects. > So look into your antenna system before you dig into your rig. You could > also hook a signal generator to the rig and see if it receives OK on all > bands with something like less than an S9 signal. Be sure to not transmit > into your generator, and/or set your tx to very low power. Good Luck > Rick KL7CW > > Sent from Mail for Windows 10 > > ______________________________________________________________ > Elecraft mailing list > Home: http://mailman.qth.net/mailman/listinfo/elecraft > Help: http://mailman.qth.net/mmfaq.htm > Post: mailto:[email protected] > > This list hosted by: http://www.qsl.net > Please help support this email list: http://www.qsl.net/donate.html > Message delivered to [email protected] -- 72, Rich Hurd / WC3T / DMR: 3142737 Northampton County RACES, EPA-ARRL Public Information Officer for Scouting Latitude: 40.761621 Longitude: -75.288988 (40°45.68' N 75°17.33' W) Grid: *FN20is* ______________________________________________________________ Elecraft mailing list Home: http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/mmfaq.htm Post: mailto:[email protected] This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html Message delivered to [email protected]
