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General Vintage Technology Discussions For general discussions about vintage radio and other vintage electronics etc. |
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17th Aug 2017, 5:20 pm | #21 | |
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Re: Telephone calls heard on MW!
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17th Aug 2017, 6:51 pm | #22 |
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Location: Hexham, Northumberland, UK.
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Re: Telephone calls heard on MW!
The problem with old cordless phones was that if you rang up and ordered something on your "secure" leaded phone, you didn't know if the person at the other end was using a cordless and being monitored for your credit card details etc.
Alan. |
19th Aug 2017, 8:22 pm | #23 |
Nonode
Join Date: Jan 2016
Location: Stafford, Staffs. UK.
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Re: Telephone calls heard on MW!
I do remember something similar but not entirely the same. On my brother's 'hifi' system if you held the headphone plug in a particular way, you could pick up broadcast radio, but in a foreign language so not sure what it was. Scary thing is his 'system' was just a turntable and amp, not supposed to be any kind of radio receiver. This behaviour disappeared after i realised he had wired earth and neutral crossed and fixed it. He works for openreach now!
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19th Aug 2017, 8:52 pm | #24 |
Dekatron
Join Date: Feb 2005
Location: West Cumbria (CA13), UK
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Re: Telephone calls heard on MW!
That is simply a poor contact acting as a diode and rectifying a radio signal.
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20th Aug 2017, 8:16 pm | #25 |
Hexode
Join Date: Jan 2012
Location: Weymouth, Dorset, UK.
Posts: 422
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Re: Telephone calls heard on MW!
I remember hearing those phones on the edge of the medium wave, in fact I once heard a call between a young lady and a male where the lady was clearly offering her favours if you know what I mean. Also whilst listening in that part of the band I discovered coastal radio stations. I was most surprised because I lived in the middle of Berkshire then! Re the foreign stations on HIFI systems my uncle had a system with long speaker leads and with the amp OFF you could here a slight whistle and faint voices especially in winter as soon as the amp was switched on the amp the effect went. I wonder if the fact that my uncle's bungalow was fed by miles of overhead power cables helped the effect
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22nd Aug 2017, 9:04 am | #26 |
Nonode
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Location: 1966-1976 Coverack in Cornwall and Helston Cornwall. 1976-present Bristol/Bath area.
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Re: Telephone calls heard on MW!
I heard many a telephone conversation on the top end of the medium wave band just above 1.6Mhz from the first generation analogue cordless phone. These used 1.6Mhz to 1.7Mhz from base station to handset and frequencies around 47Mhz from Handset back to the base station.
The next and last of generation analogue cordless phones used frequencies in the 30-40Mhz range which could cause breakthough on TV sets as one of the channels used was very close to the vision IF of 39.50Mhz.
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22nd Aug 2017, 9:19 am | #27 |
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Re: Telephone calls heard on MW!
All sorts of things can break through and be heard on audio equipment. Slightl OT for this thread I know, but I once owned a Sharp SG500 Music Centre, and, one evening, the two-way radio in a police car which was parked not far away, broke through whilst I was playing a record. This was due to the base/emitter junction of one or more transistors acting as a rectifier, though how the signal got in there I don't know, unless it was via my indoor FM Ribbon aerial.
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22nd Aug 2017, 10:16 am | #28 |
Hexode
Join Date: Oct 2012
Location: London, UK.
Posts: 499
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Re: Telephone calls heard on MW!
The legal ones used 1.7 and 47MHz, 47MHz being between 405 line TV channels 1 & 2. The illegal grey imports used 1.7MHz and 49 MHz which interfered with ch 2 and also my TV DXing of E2 from Europe.
I managed to get the radio interference people to get a particularly nearby grey one removed for this reason. |
26th Aug 2017, 11:42 am | #29 |
Pentode
Join Date: May 2011
Location: Bath, Somerset, UK.
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Re: Telephone calls heard on MW!
i also used to get this back in the 90's when listening to shortwave on a 1930's HMV radiogram but it was only my next door neighbor and all she talked incessantly about was golf!
I wouldn't have minded so much had it been about the visits from the milkman or the gasman but golf!! 😆😆 |
26th Aug 2017, 12:32 pm | #30 |
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Location: Hexham, Northumberland, UK.
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Re: Telephone calls heard on MW!
My Sister once was a bit spooked when she said she could hear a baby crying in the background sometimes when on the cordless phone. She was relieved when I explained that it was probably picking up her neighbours' baby alarm. There was in fact a new baby in the house next door. There was also someone across the road with quite a few antennas on the house (as you do) so I explained the security risk to her and she was horrified. Every analogue cordless phone should have come with a warning but I never personally saw one. Of course the newest security risk is internet connected CCTV cameras being hacked. I wouldn't have one in the house. There has been some recent footage on TV about the risks, but just riding on the back of open WiFi network hacking. (I hate that word "hack"!)
Alan. |
27th Aug 2017, 11:05 am | #31 |
Retired Dormant Member
Join Date: Jun 2015
Location: Southport, Lancs. UK.
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Re: Telephone calls heard on MW!
I remember these as the shop I worked at in the 80s used to deal with them.
JAK in Southport still hanging on there. The first one was called the Freedom Phone, then there were a few other types. They used the 1.7 Mhz range from base to hand set and 49 Mhz return. there was a fuss at the time as it was thought they might interfere with Marine comms but there were 'no wrecks and nobody drownded' and later approved units came out on the same bands. ( if enough people break the law, change the law. problem solved. as with cb radio) The BT approved one was the Freeway and it had clones badged as Tandy and Uniden. A later one was the Fidelity Wanderer which was a bit of a disaster with reliability issues, I think it caused the collapse of the firm. We used to have an 'old Bat' living next door but one who used to annoy us by trying to hi-jack our pet cat by feeding it and keeping it her house. I could hear her rabbiting on her cordless phone on my 62 set just below top band, the 62 is a transceiver, Nuff said. |