[INRAD] Switching diodes in roofing filter for the IC-775DSP

[William E. Sabin]

The MPN3404 has a recombination time of  "a Few Microseconds" and the 
HP5082-3081 has "2500ns = 2.5 microsec".  These two types appear to be 
almost identical in that respect.

Bill W0IYH

----- Original Message ----- 
From: "Thomas" <ac7a at cox.net>
To: "Charlie Mazoch Jr." <w5vin at earthlink.net>
Cc: <list at inrad.net>
Sent: Friday, November 25, 2005 10:50 AM
Subject: Re: [INRAD] Switching diodes in roofing filter for the IC-775DSP


>
> The mistake that many hams make is assuming that any PIN diode will work
> in most any application. The MPN3404 is rated for VHF switching
> applications, because its recombination time is short; a few
> microseconds. Yet, I often see the MPN 3404 used in HF RF and IF
> applicaitions. Not to say that it won't act as an RF switch, but it will
> not provide the isolation or low distortion of a more suitable HF PIN
> device. By a more suitable HF PIN device, I suggest a device like the
> HP5082-3081, with its 2500nS recombination time (1 tau).
>
>