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

[Charlie Mazoch Jr.]

Hi Bill:
 Here is a wonderful article on PIN and PN diodes. I learned the fact 
that current flow consists of only majority carriers in the Schottky 
diode.   Interesting.   73's   Charlie

http://www.microsemi.com/idx.asp?MN=435


  William E. Sabin wrote:

> 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).
>>
>>
>
>
>