[TenTec] 1208 Transverter

[Bob McGraw - K4TAX]

Comment - these transverters aren't known to be great performers in areas 
where multiple VHF and UHF commercial equipment is being operated.  Anything 
that contributes to intermod either on RX or TX can spell problems.

RX intermod produces various birdies, false signals, burps, growls, howls 
and such on receive, often covering desired signals.  On TX, radiation of 
intermod can cause interference with commercial services such as police, 
fire, ambulance and other services.  Should this happen, you will be a very 
popular person with their technical staff.  The results will be very 
"unkind".

I don't mean to poo poo your idea and use of equipment, but anything you can 
do to make it clean and keep it that way will be greatly appreciated by all 
spectrum users.

73
Bob,. K4TAX




----- Original Message ----- 
From: "Dr. Gerald N. Johnson" <geraldj at storm.weather.net>
To: <davidcuttler at yahoo.com>; "Discussion of Ten-Tec Equipment" 
<tentec at contesting.com>
Sent: Wednesday, January 14, 2009 11:58 AM
Subject: Re: [TenTec] 1208 Transverter


> On Wed, 2009-01-14 at 07:55 -0800, David Cuttler wrote:
>>
>> So what will the operational difference be if I replace the "real" pin 
>> diode with one of the other types like the 1N4007?
>>
>>
> There will greater intermod both receive and transmit with the 1N4007
> over the true PIN diode, and more than that with the 1N4148.
>
> I  know I've seen an article on the topic, probably in VHF
> Communications. Found it in the index:
> 1994/1 "Intermodulation Properties of Switching Diodes" by Dr Ing Jochen
> Jirmann, DB1NV, pages 12 - 18. Last year that article was probably
> available on-line, today I think it isn't but the publisher will sell
> back issues.
>
> It might be at:
> http://homepages.ihug.co.nz/~jaking/TS-940_02.htm#_Toc155846465, or
> might not.  Yup there are scans of the article, it will load slowly
> at the end of a long web page.
>
> 73, Jerry, K0CQ
>
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