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

[Paul Christensen]

>I believe the Argo V DOES use diode switching.  The
> pin diodes used are exotic 1N4007.

The Omni 6/6+ also uses a handful of 1N4007 diodes as part of the T/R 
circuit, particularly for the 2nd Rx port.  However, isolation 
characteristics are not nearly as good as a true PIN diode structure.  Where 
isolation is not a primary concern, the 1N4007 can be used as a low-cost, 
low/mid-power RF switch.   On the Omni 6, I was able to increase port 
isolation by better than 40 dB by replacing the 1N4007 diodes with high 
power UM2110 PIN types from Microsemi.

Port isolation on the Omni VII easily matches or exceeds what I was able to 
achieve on the modified Omni 6.

Paul, W9AC