[TenTec] OMNI VII QSK users with good ears....

[Paul Christensen]

> I'm trying to think of a modern Ten-Tec radio that doesn't use a relay for
> T/R switching, and can't think of one!

Their reed relays are plenty fast enough and I see no real benefit over PIN 
diode switching except for longevity.  Still, few relays fail in these rigs 
even after 20+ years.

I did replace the T/R relay in my Omni VII with a Matsushita/Aromat RS-12D 
reed relay, made specifically for RF switching.  While the stock Omni VII 
relay is reasonably quiet, it's possible to take the slight ticking noise to 
zero with the RS-12D.

Ten Tec used an ingenious scheme to isolate the T/R relay.  They mounted it 
on a very small PCB and cushioned it with foam.  I took their idea a step 
further and replaced the solid conductor wire with ultra-fine strand, 
silicone jacketed wire from a robotics company.

http://www.trossenrobotics.com/store/p/5224-22AWG-High-Strand-Count-Silicone-Wire-Combo-Pack-25-ft-.aspx

The new wire is super flexible and does not acoustically transmit the 
armature noise back to the PCB.  Totally silent QSK now even when placing 
the ear on the cabinet.

Paul, W9AC