Steve, You are correct. Best to use one of these, but did not know if he had built one. Often using an antenna on the sig gen can work, but the "ISOLATED" Tee would be better.
73, ron, n9ee/r >From: "Steve Bosshard (NU5D)" <[EMAIL PROTECTED]> >Date: 2008/07/08 Tue AM 09:05:56 EDT >To: [email protected] >Subject: Re: [Repeater-Builder] New Repeater Desense Problems > >Don't leave out the isolated TEE between the duplexer and dummy load, >Ron. Hi, Steve NU5D > >Ron Wright wrote: >> Bill, >> >> In finding desense first one must locate the problem. A given. >> >> I would start with putting GOOD dummy load on the duplexer output and do a >> desense test. This can be done with a local signal gen where you can vary >> the gen output and keying and unkey the transmitter. You should see no >> difference in the received signal with tx keyed or unkeyed. >> >> If you do then the desense is in the repeater. Next do the same test with >> the dummy load on the transmtter only. This will test for the desense being >> inside or outside the radio part of the repeater. >> >> I would look at your LMR400 and antenna. I think the LMR400 is a double >> shielded cable with different metals for the 2 shields. This is a no no in >> duplexed system. It generates noise. It has been discussed here on this >> board many many times and for good reason. If this is a problem replace >> with a good heliax. It is worth the cost. >> >> This is a start. >> >> 73, ron, n9ee/r >> >> >> >> > > Ron Wright, N9EE 727-376-6575 MICRO COMPUTER CONCEPTS Owner 146.64 repeater Tampa Bay, FL No tone, all are welcome.
