[RFI] RFI resistant telephones
Sun, 1 Dec 2002 12:00:05 -0500
I picked up the Radio Shack 43-586B a couple years ago which seems to be
pretty immune. I use it for the same purpose you are looking at. Around
$20 as I recall. It is probably like the "clear phone" that Bill, W7TI,
73 and GL, George .. W1ZT
----- Original Message -----
From: "Edward F. Douglass" <firstname.lastname@example.org>
Sent: Sunday, December 01, 2002 10:54 AM
Subject: [RFI] RFI resistant telephones
> I am new to the list. I have read the last few month's "traffic" but have
> not found a thread dealing with telephone RFI, and RFI-resistant
> in particular.
> As part of my diagnosis, I need an RFI-resistant telephone in order to
> determine if phone company equipment (lightning arrester, RF bypass
> capacitors, or other devices) are rectifying my transmit RF and putting
> audio on the phone line.
> All of my phones are sensitive to RF because in spite of a variety of
> chokes and filters, I hear my SSB audio on every phone. Some are less
> sensitive than others but they all have objectionable audio on them. Of
> course, the audio could be coming from phone company equipment or faults
> my phone wiring as well as my own phones. If either of these happening,
> amount of filtering or choking will solve the interference problem.
> The ARRL RFI tech site mentions the Radio Shack ET-171 as a phone that is
> pretty resistant to RF. However, my Radio Shack catalog no longer lists
> this model.
> I am aware of the "bullet proof" phones from TCE Laboratories and Pro
> Distributors but they cost $80. I would like to find a less expensive
> Can anyone recommend a phone that I could buy at a WalMart, Target, Radio
> Shack store (or similar) that is RF resistant? Please specify make and
> Or does someone have an RF resistant instrument that I could borrow for
> testing purposes? I would be willing to pay shipping both ways.
> Finally, has anyone found that re-wiring their residential phone system
> with Category 5e data cable has made a significant improvement in RF
> to make the cost and effort worth while?
> 73 de Ed, AA9OZ
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