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
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