If you just can't get access to a VNA and someone who knows how to use it, having a 50-ohm attenuator on hand to put between the duplexer and the handheld or mobile rig can help a great deal. They can be found with BNC connectors on hamfest junk tables, (make sure they're 50 ohms,) or homebrewed fairly easily as long as you're careful with shielding.
A 6-dB or 10 dB pad will still pass all the signal you need from the generator. ----- Original Message ----- From: Eric Lemmon To: [email protected] Sent: Sunday, September 20, 2009 10:25 AM Subject: RE: [Repeater-Builder] UHF Duplexers The most obvious problem when using a handheld radio is that the antenna connection on a handheld is very seldom optimized at 50 ohms...a VNA has precise 50 ohm matches on all ports... .
