[TenTec] Re: Paragon Question - Lack of sensitivity

[Steve Baron - KB3MM]

What diodes do they use?

----- Original Message ----- 
From: "Tommy" <aldermant at alltel.net>
To: <tentec at contesting.com>
Sent: Thursday, February 03, 2005 14:37
Subject: Re: [TenTec] Re: Paragon Question - Lack of sensitivity


> 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 at uiuc.edu>
> To: <tentec at 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 at juno.com" <ultrafixedwing at juno.com>
> >>Subject: Re: [TenTec] Re: Paragon Question - Lack of
> > sensitivity
> >>To: tentec at 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 at contesting.com
> > http://lists.contesting.com/mailman/listinfo/tentec 
> 
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