H. M. 'Puck' Motley W4PM wrote:
>
> I have the feeling that the pin diodes in question are a modification
> suggested in an article by Ulrich Rhode (not sure of the spelling of his
> name) a few years back concerning 2nd order IMD in modern rigs. One of
> the rigs mentioned was the Paragon. The article stated that by replacing
> the common switching diodes used to switch the receiver front end band
> pass filters with a certain type of pin diode, 2nd order IMD could be
> improved. Maybe some of our more technically oriented folks remember this
> article and can comment in greater detail. This is all I remember so if
> you have additional questions don't ask me!
>
Thanks, Puck. I was certain it was something Rohde said, just wasn't
quite sure when or what the exact reason was. I just spoke to Ten Tec
about this, and they actually said they had tested different types of
diodes to switch the Paragon's receiver filters, and settled on regular
switching diodes because there wasn't much difference with other types.
So, I guess replacing the receiver filter switching diodes with PIN or
other (hot carrier, etc.) types is probably a mod that some users have
done themselves. At least I know for sure it's not a factory
modification.
Is there anyone out there who knows this for sure? Has anyone done the
aforementioned mod? I know one fellow recently mentioned in a message
that a rig he had for sale had the mod. Now I'll go search for the Rohde
article. 8^)
73, KE3KR
--
chuck
Chuck Murcko
The Topsail Group, West Chester PA USA
chuck@topsail.org
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