Radio Shack CLEAR PHONE 43-858 - UK Vintage Radio Repair and Restoration Discussion Forum

dave walsh · 27th Jun 2015, 8:06 pm

I know even less about telephones than most gear but I have done tel point installations from the Master. I had a success with a Logic phone this morning. The "hook switch" [as the Americans seem to call it] was not disabling the line when the handset was in place. On examination it seemed as though I would have to try "flowing" the solder connections but switch cleaner resolved it

I was emboldened to move on to......

The Clear Phone! I bought it from Tandy in Bury many years ago but it's in good nick. I told the sales assistant I needed to get my aged mother to answer calls. He said "I got one of these for my aunt-it's loud and covered with flashing lights"-you can't go wrong" yes you can! When I saw the colourful exposed electronics I really wanted it for myself

It's still operational but only in the way that people sometimes say "my record player/radio works but it won't revolve/pick up stations" ie the lights are flashing but [audio wise] there is no one at home-a distinct lack of ring tone. The one inch little spkr/buzzer/contact device is detached from it's mount but the three wires to it are intact and seem to have continuity. Any comments from those in the know would be greatfully received

Is this "transducer type" part likely to have failed or is it probaly the electronics? You can take calls ok if you notice the lights but that's it at present.

Dave W

TonyDuell · 27th Jun 2015, 8:43 pm

By 'ring tone' I assume you mean the noise it makes when it receives an incoming call, and not something normally hard through the earpiece.

If the piezo buzzer disk (I've seen them called 'benders' -- and in serious technical manuals) has 3 wires, then one of them is a feedback signal. This suggests to me that the ringer is a simple transistor oscillator and not one of the many ringer ICs, which only need 2 wires to the piezo buzzer. Yes, the piezo buzzers can fail, but I would suspect the oscillator transistor first. Trace the wires back to find it.

Or an even more silly fault. Is there a ringer on/off or volume switch? If so, check that is not open-circuit. Switches and connectors seem to account for most of the faults I get....

julie_m · 27th Jun 2015, 9:44 pm

..... And don't forget to try it through an ADSL filter with a ringing capacitor, in case it is expecting to see ringing volts on pin 3 of the socket. (I think this used to be a requirement of the "green circle" approvals programme, in the days when they were a bit more paranoid about risking subs'-side equipment blowing up their exchanges.)

TonyDuell · 27th Jun 2015, 9:54 pm

Yes, at one time I think a telephone had to use pin 3 for ringing in order to get approval. Now it doesn't seem to matter (and I am sure I read somewhere that a plain 2 wire telephone, connecting to 2 and 5, and with an internal ringing capacitor is actually less likely to cause problems with ADSL).

IIRC the main reason for pin 3 was so that any telephone could short out all the bells when it was off-hook (effectively connecting pin 3 to pin 5) and thus prevent 'tinkle' when pulse dialing. Quite why this was thought to be so important is beyond me. I've never known anyone who was really bothered by said tinkle.

Anyway, gettibg back to this telephone, the OP did say that the ringing lamp(s) still worked. It would be a very odd design to wire said lamps in a different way to the ringer (e.g. with an intenal ringing capacitor for one and using terminal 3 on the socket for the other). Of course without a schematic there is no way to be sure, but I would look for other causes first.

Dave Moll · 27th Jun 2015, 10:35 pm

Or is the OP referring to a lack of dial tone?

dave walsh · 27th Jun 2015, 10:49 pm

No not dial tone that's missing Tony/Dave-no ringing out just flashing as I said. It's probaly me not knowing the right terms. Thanks for the responses all. If it's a transistor Tony that may be more difficult for me. Your point that what's driving the lights should work the audio is interesting. I will try to check it all out again-especially the mute switch but I did look at it earlier. It's already on an ADLS [I tried it without] AJS but thanks anyway. I feel that I'm a bit further on now!
Dave

27th Jun 2015, 8:06 pm	#1
dave walsh Dekatron Join Date: Jan 2006 Location: Ramsbottom (Nr Bury) Lancs or Bexhill (Nr Hastings) Sussex. Posts: 5,817	Radio Shack CLEAR PHONE 43-858 I know even less about telephones than most gear but I have done tel point installations from the Master. I had a success with a Logic phone this morning. The "hook switch" [as the Americans seem to call it] was not disabling the line when the handset was in place. On examination it seemed as though I would have to try "flowing" the solder connections but switch cleaner resolved it I was emboldened to move on to...... The Clear Phone! I bought it from Tandy in Bury many years ago but it's in good nick. I told the sales assistant I needed to get my aged mother to answer calls. He said "I got one of these for my aunt-it's loud and covered with flashing lights"-you can't go wrong" yes you can! When I saw the colourful exposed electronics I really wanted it for myself It's still operational but only in the way that people sometimes say "my record player/radio works but it won't revolve/pick up stations" ie the lights are flashing but [audio wise] there is no one at home-a distinct lack of ring tone. The one inch little spkr/buzzer/contact device is detached from it's mount but the three wires to it are intact and seem to have continuity. Any comments from those in the know would be greatfully received Is this "transducer type" part likely to have failed or is it probaly the electronics? You can take calls ok if you notice the lights but that's it at present. Dave W

27th Jun 2015, 8:43 pm	#2
TonyDuell Dekatron Join Date: Jun 2015 Location: Biggin Hill, London, UK. Posts: 5,208	Re: Radio Shack CLEAR PHONE 43-858 By 'ring tone' I assume you mean the noise it makes when it receives an incoming call, and not something normally hard through the earpiece. If the piezo buzzer disk (I've seen them called 'benders' -- and in serious technical manuals) has 3 wires, then one of them is a feedback signal. This suggests to me that the ringer is a simple transistor oscillator and not one of the many ringer ICs, which only need 2 wires to the piezo buzzer. Yes, the piezo buzzers can fail, but I would suspect the oscillator transistor first. Trace the wires back to find it. Or an even more silly fault. Is there a ringer on/off or volume switch? If so, check that is not open-circuit. Switches and connectors seem to account for most of the faults I get....

27th Jun 2015, 9:44 pm	#3
julie_m Dekatron Join Date: May 2008 Location: Derby, UK. Posts: 7,735	Re: Radio Shack CLEAR PHONE 43-858 ..... And don't forget to try it through an ADSL filter with a ringing capacitor, in case it is expecting to see ringing volts on pin 3 of the socket. (I think this used to be a requirement of the "green circle" approvals programme, in the days when they were a bit more paranoid about risking subs'-side equipment blowing up their exchanges.) __________________ If I have seen further than others, it is because I was standing on a pile of failed experiments.

27th Jun 2015, 9:54 pm	#4
TonyDuell Dekatron Join Date: Jun 2015 Location: Biggin Hill, London, UK. Posts: 5,208	Re: Radio Shack CLEAR PHONE 43-858 Yes, at one time I think a telephone had to use pin 3 for ringing in order to get approval. Now it doesn't seem to matter (and I am sure I read somewhere that a plain 2 wire telephone, connecting to 2 and 5, and with an internal ringing capacitor is actually less likely to cause problems with ADSL). IIRC the main reason for pin 3 was so that any telephone could short out all the bells when it was off-hook (effectively connecting pin 3 to pin 5) and thus prevent 'tinkle' when pulse dialing. Quite why this was thought to be so important is beyond me. I've never known anyone who was really bothered by said tinkle. Anyway, gettibg back to this telephone, the OP did say that the ringing lamp(s) still worked. It would be a very odd design to wire said lamps in a different way to the ringer (e.g. with an intenal ringing capacitor for one and using terminal 3 on the socket for the other). Of course without a schematic there is no way to be sure, but I would look for other causes first.

27th Jun 2015, 10:35 pm	#5
Dave Moll Dekatron Join Date: Feb 2005 Location: West Cumbria (CA13), UK Posts: 6,127	Re: Radio Shack CLEAR PHONE 43-858 Or is the OP referring to a lack of dial tone? __________________ Mending is better than Ending (cf Brave New World by Aldous Huxley)

27th Jun 2015, 10:49 pm	#6
dave walsh Dekatron Join Date: Jan 2006 Location: Ramsbottom (Nr Bury) Lancs or Bexhill (Nr Hastings) Sussex. Posts: 5,817	Re: Radio Shack CLEAR PHONE 43-858 No not dial tone that's missing Tony/Dave-no ringing out just flashing as I said. It's probaly me not knowing the right terms. Thanks for the responses all. If it's a transistor Tony that may be more difficult for me. Your point that what's driving the lights should work the audio is interesting. I will try to check it all out again-especially the mute switch but I did look at it earlier. It's already on an ADLS [I tried it without] AJS but thanks anyway. I feel that I'm a bit further on now! Dave Last edited by dave walsh; 27th Jun 2015 at 10:54 pm.