[FoxHunt] Attenuator

Sun, 21 Apr 2002 21:46:36 -0400

Yes, I would like to see a schematic also.  Thanks for the App Note Bob.

73, Jess, w4pqk

-----Original Message-----
From: Uwe DF7BL <[email protected]>
To: [email protected] <[email protected]>
Date: Sunday, April 21, 2002 3:15 PM
Subject: Re: [FoxHunt] Attenuator

>Hi Bob, ist there a way to get the schematic of that sniffer. May be
direkt.
>Sorry for the list but mailman does not accept attachments.
>73 de uwe df7bl
>
>Bob schrieb:
>>
>> My friend Tony has built a sniffer around the Analog Devices
>> Logrithmic amplifier chip. Here is his report...
>>
>>    "This week I finished my new sniffer with the AD 8307. It
>> is
>> the best I have ever used. I combined the 8307 and a ticker
>> that goes up
>> in tone with more RF. It starts to tick at -107 dbw and has
>> 70 db dynamic range to the high tone. I then can switch in
>> 30 and 35 db
>> attenuators to numb it  60 db. The lost 5 db is some kind of
>> leakage. (marginal shielding)   I think I did the
>> measurements correctly.    I can stand in my yard and key a
>> repeater 10 miles away and it
>> will start to tick when pointed in that direction. With the
>> switches in, -60db, I can DF my repeater, 80 watts at 25
>> feet."
>>
>> I suggested to Tony that he replace the toggle switches with
>> relays and use bypass feedthroughs for the wires to get
>> better shielding. He is working on numbing down the 8307 as
>> well. It is one hot chip It takes almost no support parts
>> and has a 90 dB dynamic range if you can figure out how to
>> get them all.
>>
>> cut cut....
>
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