Re: [TenTec] Re: Paragon Question - Lack of sensitivity

["Tommy" <aldermant@alltel.net>]

I'm not sure about the Paragon, but the Omni 6 series radios do use 
cheap JA pin-diodes. (which turned out to be the best one's to use!)

I fell for the idea of replacing all of the Ten Tec installed 
pin-diodes for the 'better' Hewlett-Packard pin diodes, which were 
quite expensive. Course when you change to the HP pin-diodes, you 
have to adjust the current throuh the diodes so they work correct. 
Bottom line was I wasted some nickles and a heck of a lot of time, 
as I found no improvement at all in performance of the Omni 6 
receiver. Actually I would say that the HP pin diodes did not 
preform as well as what Ten Tec had in the radio origanally.

Of course the diodes that switch the band-pass filters (hopefully) 
do not see and are not switched by RF at all. It's all DC switching. 
To obtain the same or better performance when you replace pin-diodes 
you really have to know what current to run through the diodes to 
obtain the best isolation, etc. You are taking some chances when you 
replace Ten Tec component's with something that is 'better'.

I think I have found, over the years of using Ten Tec radio's, the 
best way to 'improve' them is to keep the covers on them at all 
times and keep your paw's out of them...unless of course you adding 
a roofing filter. Not a heck of a lot needs improvement anyway!

Tom - W4BQF

----- Original Message ----- 
From: <c-hawley@uiuc.edu>
To: <tentec@contesting.com>
Sent: Thursday, February 03, 2005 9:16 AM
Subject: Re: [TenTec] Re: Paragon Question - Lack of sensitivity


> If these are the diodes that switch in and out the input
> band pass filters, you are better off with pin diodes which
> switch much slower than 4148s. The reason is so that strong
> incoming rf does not switch the diodes that are supposed to
> be on (or off) for the band you are using. This was a big
> issue which became popular about 10 years ago. There are
> some kits available to convert the fast switching diodes to
> pin diodes. But, don't go and wholesale replace every diode
> in sight. I think some of these kits were somewhat ill
> advised. Your receiver may use pin diodes already in many
> places.
> Chuck, KE9UW
>
> ---- Original message ----
> > Date: Wed, 2 Feb 2005 15:35:58 GMT
> > From: "ultrafixedwing@juno.com" <ultrafixedwing@juno.com>
> > Subject: Re: [TenTec] Re: Paragon Question - Lack of
> sensitivity
> > To: tentec@contesting.com
> >
> >
> > Will a 1N914/4148-Type Diode work in the Paragon front end?
> It's a silicon switching diode. If so, I'll run out and get
> a handfull.
> > Thanks,
> > Paul
> > KS2S
> _______________________________________________
> TenTec mailing list
> TenTec@contesting.com
> http://lists.contesting.com/mailman/listinfo/tentec 

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