Towertalk
[Top] [All Lists]

Re: [TowerTalk] Relay Box Measurements

To: "'Jim Lux'" <jimlux@earthlink.net>, <towertalk@contesting.com>
Subject: Re: [TowerTalk] Relay Box Measurements
From: "Jeff DePolo" <jd0@broadsci.com>
Date: Sun, 26 Aug 2012 13:27:44 -0400
List-post: <towertalk@contesting.com">mailto:towertalk@contesting.com>
> when you do the measurements (using some form of VNA, I 
> presume), do you 
> cal with a set of standards with UHF connectors, or something else?

You're better off using lab-grade test cables with constant impedance
connectors (N, SMA, TNC, etc.) and a precision cal kit to do the cal, and
then use a high-quality adapter to get to UHF to connect to the DUT.  Unless
you're dealing with short wavelengths, the added electrical length of the
adapter (maybe 3/4"?) isn't appreciable (3/4" is only a little over half a
degree at 10m), but if you're a purist you could always offset the complex Z
accordingly (Smith Chart or electronic equivalent thereof). Insertion loss
of a quality N to UHF adapter is negligible at HF.

                                --- Jeff WN3A 


_______________________________________________



_______________________________________________
TowerTalk mailing list
TowerTalk@contesting.com
http://lists.contesting.com/mailman/listinfo/towertalk

<Prev in Thread] Current Thread [Next in Thread>