Quest for AM radio with telescoping antenna
I've mentioned the Gilligan's Island radio (with the telescoping antenna) before:
https://wb9kzy.blogspot.com/2022/05/fallout-shelter.html
Well I finally found an AM radio with a telescoping antenna in an old Esquire magazine, the Westinghouse 666P-5:
https://wb9kzy.blogspot.com/2022/05/fallout-shelter.html
Well I finally found an AM radio with a telescoping antenna in an old Esquire magazine, the Westinghouse 666P-5:
source: https://archive.org/details/Esquire-Magazine-1958-05/page/n71/mode/2up
Let us take a look at the schematic of the Westinghouse courtesy of Beitman's 1959:
https://archive.org/details/BeitmansMostNeededRadioDiagrams/1959/page/n159/mode/1up
The 666P-5 has an ugly power supply (no transformer, shame on you Westinghouse !) - with the directly heated cathodes I bet it started to hum as soon as the filter caps began to dry out. But it does have a tuned RF amplifier so just that extra oomph for portable use, say on a vacation up-north ? I'd classify this as a "3-gang" type of radio - most AM radios just had a two section variable cap, one section for the oscillator, the other to tune the input bandpass - antenna loop. But the 666P-5 has another cap/inductor to tune the bandpass before the RF amplifier. This was present in the medium price shortwave receivers like the Radio Shack DX-160 but absent in the cheaper shortwaves like the Hallicrafters S-120.
It is interesting to see how the rod antenna is hooked into the circuit. There is a switch which seems to normally short things out when the antenna is down. When the rod is pulled out the switch opens and the rod is capacitively coupled to the loopstick. This would be pretty easy to add to any AM radio to pep things up. In fact I have seen something similar in the 1974 version of 101 Electronic Projects:
source: https://archive.org/details/101ElectronicsProjects1974/page/18/mode/2up
also this even simpler idea:
source: https://archive.org/details/101ElectronicsProjects1974/page/24/mode/2up
Westinghouse also had other portables with the extendable antenna but they didn't have the RF amp:
https://archive.org/details/BeitmansMostNeededRadioDiagrams/1959/page/n158/mode/1up
Now crazy 4-gang designs were also available from Hallicrafters in some of their receivers like the SX-88 but yikes, the price of getting 4 caps tuned in parallel to track was high.
In any case if I had known more about antennas as a kid I would have worried less about not having the extendable antenna on the radio - or of course if I had known that due to the nearby Nike site we all would have been toasted by a Soviet attack no matter what kind of radio we had :)
I've never seen the Beitman's books before, kind of a no-nonsense (few photos) version of the Sams Photofacts, very useful, also available on Worldradiohistory.com.
Best Regards,
Chuck, WB9KZY
http://wb9kzy.com/ham.htm
Let us take a look at the schematic of the Westinghouse courtesy of Beitman's 1959:
https://archive.org/details/BeitmansMostNeededRadioDiagrams/1959/page/n159/mode/1up
The 666P-5 has an ugly power supply (no transformer, shame on you Westinghouse !) - with the directly heated cathodes I bet it started to hum as soon as the filter caps began to dry out. But it does have a tuned RF amplifier so just that extra oomph for portable use, say on a vacation up-north ? I'd classify this as a "3-gang" type of radio - most AM radios just had a two section variable cap, one section for the oscillator, the other to tune the input bandpass - antenna loop. But the 666P-5 has another cap/inductor to tune the bandpass before the RF amplifier. This was present in the medium price shortwave receivers like the Radio Shack DX-160 but absent in the cheaper shortwaves like the Hallicrafters S-120.
 |
| note the dotted line on the variable cap indicating connection to the other sections of the cap |
It is interesting to see how the rod antenna is hooked into the circuit. There is a switch which seems to normally short things out when the antenna is down. When the rod is pulled out the switch opens and the rod is capacitively coupled to the loopstick. This would be pretty easy to add to any AM radio to pep things up. In fact I have seen something similar in the 1974 version of 101 Electronic Projects:
also this even simpler idea:
Westinghouse also had other portables with the extendable antenna but they didn't have the RF amp:
https://archive.org/details/BeitmansMostNeededRadioDiagrams/1959/page/n158/mode/1up
Now crazy 4-gang designs were also available from Hallicrafters in some of their receivers like the SX-88 but yikes, the price of getting 4 caps tuned in parallel to track was high.
In any case if I had known more about antennas as a kid I would have worried less about not having the extendable antenna on the radio - or of course if I had known that due to the nearby Nike site we all would have been toasted by a Soviet attack no matter what kind of radio we had :)
I've never seen the Beitman's books before, kind of a no-nonsense (few photos) version of the Sams Photofacts, very useful, also available on Worldradiohistory.com.
Best Regards,
Chuck, WB9KZY
http://wb9kzy.com/ham.htm
