"Gary Smith" wrote in message
...
Hi, i would like to build a variable attenuator for 450-500MHz. It will be
used for RDF assistance.
Could people please give me construction details of different designs or
different ideas on the topic.

I woould love an electronic RDF unit but havn't found many kits here in
Australia so an attenuator will be
a good start.

Thanks


Gary

Gary:

Building is an option, but you can also find some nice commercial units
on eBay which may have simply failed a calibration check. There are
several brands of attenuators out there retired from shops and labs
regularly.

I purchased a few HP 355D VHF attenuators, which are 0 - 120 dB step
attenuators made for 50-ohms from 0 to 1000MHz with a rotary switch.
A couple were just out of calibration (not a problem for my application),
and the cheaper one had some problems with individual steps that could be
repairable. I think I've paid $40 to $90 each for these last year.

The cheapest I found were Kay Electronics 0 - 100 dB attenuators with
nine sections switched by toggle switches. A couple on eBay are about to
sell for less than $20 as I type this!

Jeff