[RFI] RFI resistant telephones
Mon, 2 Dec 2002 19:20:33 -0500
Radio Shack has an extensive set of specifications their vendors have to meet. Last I checked with RS, they require the phones to exhibit a modicum of immunity to RF fields. That is why many of the RS phones have been somewhat RFI-resistant.
While not guaranteed against RFI, most of the time, when a customer returns a RS product, it is taken back with no questions asked.
Ed Hare, W1RFI
225 Main St
Newington, CT 06111
> -----Original Message-----
> From: Edward F. Douglass [mailto:firstname.lastname@example.org]
> Sent: Sunday, December 01, 2002 10:54 AM
> To: email@example.com
> 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 telephones
> 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 in
> my phone wiring as well as my own phones. If either of these
> happening, no
> 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 test
> 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 pickup
> to make the cost and effort worth while?
> 73 de Ed, AA9OZ
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