headphone to telephone adaptor

[chekald]

I thinking of piecing together of quick adaptor so that I able to plug my stereo headphones in place of my phones handset. I wondering if it is just as easy as buying a RJ-11, stereo plugs and wiring the right connectors together? I’m wondering if there will be an impedance problem or if I’ll need to amplify the signal from the phone.

At least once a month I have to listen in on an hour or two telephone conference call. I hate holding the receiver to my ear the whole time and wish to kind to my office mates by sparing them the tedium of my listening by speakerphone. I was thinking that I might be able to actually get work done if I had my hands free.

 

[OperaHouse]

Isn't it amazing that the people with the least to say take the longest. I would put the headphones in series (connect to the tip and ring) to increase the impedence. You will likely have enough volume.

 

[VEBill]

"...headphones...connected..." Ringing voltage on the telephone line can be about 90 Vac. I personally wouldn't want to connect it directly to headphones on my skull.

Radio Shack (Tandy), and similar outfits, usually have little devices that connect the telephone line to a cassette tape recorder so that calls can be automatically recorded. They're fairly cheap (~US$10).

The above device would provide a good starting point. If you can mute the telephone mic, then you could connect it to an amplifier (portable stereo Aux in) and kick back to listen.

One advantage is it is all off the shelf.

 

[IRstuff]

Costco sells an RF linked phone set with heads-free headset capability for about $170. You can use tany handset as a speakerphone and you can plug a standard headset into any handset and carry in around on your belt.

If you look around, you'll probably find a cheaper version



TTFN

 

[VEBill]

One thing to watch out for is that some business telephone systems (especially multi-line) may use normal RJ-11 jacks, but the signals aren't always the same as the normal standard.

 

[OperaHouse]

While he did say "RJ-11", that might have really intended to be "RJ-11 like connector" since he also said "of my phones handset". The handset would not have any ringing voltage and would probably be fairly low impedence.

 

[DaveKillens]

I just bought my boss a telephone headset that plugs into the handset cord. It can be used on any kind of phone, or line (single, or multiple business. It can easily be switched between handset and headset, just the flick of a switch. It is manufactured by a major telephone accessory manufacturer.

 

[homeyv]

I know this is an old post, but did you ever make the attachment? I have actually trying to purchase one. With no luck I am thinking of making one.

 

[homeyv]

I forgot to mention that the attachment I am making is for a headset with two seperate plugs, one for mic and the other for the speakers.

 

[WA6DZS]

The maker to look for is probably Plantronics, although several others are probably in the business by now. Google for [telephone headset] and you'll find a wealth, I'm sure. I used to get a semi-annual catalog of that stuff, but been out of the phone biz a while now. The gadget will have a little modular plug (narrower than the RJ-11) that plugs into the handset jack, and will have a mute switch so you're not breathing into everybody's ear on the conference bridge. Actually, Plantronics made a slick little unit that was an ear-plug (with several sized ear inserts to fit), a mic tube, and a glasses-clip (or you could use the supplied headband.) Nicest was, it was TINY - and light. Used a pair of them at El Toro MARS (N0MET) in '70-'72, running back-to-back phone patches. We were tight with the Anaheim 500 Unit operators, and they pointed us to them.

 

[chekald]

Ok, so I tried the simple route. I cut apart a cheap Y-spliter for headphones and wired the female jacks to a RJ-11 jack. I unplug the handset (receiver) and it's plug is smaller than an RJ-11 but the clip geometry is the same and the pins line up. So after a bit of trial and error I figured out the pin assignment (1&3 were speaker, 2&4 were the mic).

It worked but volume is a bit lower than the handset.
Theres also some buzzing when the handset in the cradle and little sqweak when it is first removed from the cradle before I get the dial tone. I guess I'd need to amp the signal for it to work well but that would require power and I was hopeing to avoid that much complexity.

Oh well, I paid my $5 (cost of parts) and I learned.