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588relaynoise [2007/08/18 23:58]
n5na created
588relaynoise [2007/08/21 11:52] (current)
n5na
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 Paul, W9AC Paul, W9AC
 +
 +----
 +**August 19, 2007**
 +
 +I received several private replies concerning this mod.  First, previous Omni transceivers also used nearly-silent reed relays for 
 +T/R switching -- in addition to the loud amplifier PTT key line relay.  You may have thought your Omni used solid-state T/R 
 +switching, but if you were to listen closely, you would hear the slight "ticking" of the reed relay during T/R transitions.
 +
 +The Omni VII uses a HV transistor for amplifier switching, leaving only a small signaling relay for the T/R switching function.  But 
 +this relay is a bit noisier than RF reed relays I've used in the past. 
 +
 +The Aromat/Matsushita relay I purchased for the project is a model RSD-12V.  There's a guy on the popular Internet auction site that 
 +sells them for about $11 each.  Also, AG6K sells them.  These are superb RF relays that switch in ~ 1.0 ms without the addition of an 
 +accelerator circuit.    
 +
 +The 22 AWG flexible silicone wire was purchased from Trossen Robotics:
 +
 +http://www.trossenrobotics.com/store/p/5224-22AWG-High-Strand-Count-Silicone-Wire-Combo-Pack-25-ft-.aspx
 +
 +Paul, W9AC
 +