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 Post subject: Wavemagnets in Zenith Consoles
PostPosted: Dec Tue 05, 2017 12:32 pm 
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Joined: Jan Thu 01, 1970 1:00 am
Posts: 2544
Location: England
Were these tuned or un-tuned?

I know they could be rotated but that doesn't give a clue as either would benefit from that. If tuned I wonder how well they track?

Useable on all wavebands?

More interested in the Console ones but if the TransO work differently then that would be interesting as well

Didn't find anything about workings on the Web only Ebay selling bits and vague pictures of them including stuck on rail car windows: did anyone really do that?

thanks Gary


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 Post subject: Re: Wavemagnets in Zenith Consoles
PostPosted: Dec Tue 05, 2017 3:17 pm 
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Joined: Jan Mon 16, 2012 4:15 pm
Posts: 3619
Location: Near Brandon, Iowa
AFAIK all Wavemagnets were tuned loops. Like all loops, they were directional and it was desirable to be able to rotate the antenna in order to maximize reception. Some Wavemagnets ("shielded Wavemagnets") had thin metal plates flanking the plane of the coil, in order to provide a degree of interference suppression by blocking the electric wave component of the radio signal. If by "tracking" you are asking how they performed across the entire broadcast band, the answer is "very well".

The Wavemagnet provided a measure of signal pickup for the shortwave bands but for best reception on these bands an external longwire antenna was needed.

When the first Trans Oceanics were manufactured, railroad passenger travel was an extremely common means of transportation. It was also relatively slow and boring. No doubt the TO's demountable antenna got put to good use by travelers who were well-heeled enough to afford one of these somewhat expensive radios.


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 Post subject: Re: Wavemagnets in Zenith Consoles
PostPosted: Dec Tue 05, 2017 4:32 pm 
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Joined: Jan Thu 01, 1970 1:00 am
Posts: 2544
Location: England
Thanks for that.

Yes! correct on my tracking query.

So multi-turn, probably Litz wire. Expected to use a Long Wire for the SW.

Gary


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 Post subject: Re: Wavemagnets in Zenith Consoles
PostPosted: Dec Wed 06, 2017 1:59 am 
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Joined: Nov Thu 30, 2017 4:58 pm
Posts: 6
I'm currently restoring a Zenith console with a Wavemagnet and I'm finding that it's an excellent antenna. Right now, the chassis is on my workbench in the basement, and I'm in a bit of a fringe area, but I'm getting great reception. I've also found that is can augment my long wire antenna and improve reception.


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 Post subject: Re: Wavemagnets in Zenith Consoles
PostPosted: Dec Wed 06, 2017 2:40 am 
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Joined: Jun Wed 08, 2011 2:33 am
Posts: 6090
Location: Ohio 45177
I once owned an 11-S-474 console with the box shaped wavemagnet in back. Of course one could access it at the rear of the set and rotate for best reception but that would be inconvenient to do very often. I wonder if they ever considered a pulley on the front of the most expensive sets to make it more convenient. I suppose daytime listeners merely set it to where it seemed satisfactory for a few stations they listened to regularly. My set was excellent for pulling in quite distant stations with good sensitivity and selectivity, and sounded quite good on even distant musical programming. I payed only 75$ for it. I believe the chassis had been restored, but it had some finish and grille cloth wear. I eventually gave it away to another enthusiast after finding a correct cosmetic restoration impractical for such a large set, in my vicinity.


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 Post subject: Re: Wavemagnets in Zenith Consoles
PostPosted: Dec Wed 06, 2017 3:36 am 
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Joined: Jan Mon 16, 2012 4:15 pm
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Location: Near Brandon, Iowa
wazz wrote:
I once owned an 11-S-474 console with the box shaped wavemagnet in back. Of course one could access it at the rear of the set and rotate for best reception but that would be inconvenient to do very often. I wonder if they ever considered a pulley on the front of the most expensive sets to make it more convenient. I suppose daytime listeners merely set it to where it seemed satisfactory for a few stations they listened to regularly....

I'm not sure if Zenith ever produced a set where the Wavemagnet could be rotated by a front-panel knob, but several contemporary manufacturers did. I own two circa 1941 consoles with this feature: one from Firestone, and the other from RCA. RCA wasn't consistent with this feature over its model lineup- I suppose that it could have been a "trial balloon" feature to see if it caught on or not.

By the 1950s most higher-end German sets had knob-rotatable ferrite loop antennas. Quite a few "budget" sets did, also. For whatever reason, USA-made consoles- even expensive ones- seem to have mostly abandoned the rotatable loop antenna by the 1950s, opting for a simple unshielded loop glued to a sheet of cardboard that in turn was stapled to the rear of the cabinet. Maybe this reflected the general interest trend decline in radio (due to the rise of television) in the postwar USA.


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 Post subject: Re: Wavemagnets in Zenith Consoles
PostPosted: Dec Wed 06, 2017 8:01 am 
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Location: Oxford, MI
The Zenith T-Os used the Wave-Magnet for broadcast use only. The Wave-Rod antenna was the go to for all shortwave bands. However the first two models, the 7G605 and 8G005, also employed a special Short Wave-Magnet which was used for shortwave reception when the rod antenna cannot be used like in planes, trains and automobiles. It's a double turn loop with a series of fixed and variable capacitors switched in for each band in addition to the tuning circuitry on the chassis. It also only worked for the 31M, 25M and 19M bands. This costly and operationally challenging feature was dropped on the G500 and all subsequent Trans-Oceanics. I must say it works pretty well though if you know how to use it.

Attachment:
T-O Patent PP3.jpg
T-O Patent PP3.jpg [ 60.69 KiB | Viewed 211 times ]


Attachment:
T-O Patent PP5.jpg
T-O Patent PP5.jpg [ 57.85 KiB | Viewed 211 times ]

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 Post subject: Re: Wavemagnets in Zenith Consoles
PostPosted: Dec Wed 06, 2017 9:26 am 
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Joined: Jan Thu 01, 1970 1:00 am
Posts: 2544
Location: England
It was a great idea for consoles as usually they are mostly a big empty box.

thanks for the info Gary


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 Post subject: Re: Wavemagnets in Zenith Consoles
PostPosted: Dec Wed 06, 2017 4:46 pm 
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Joined: Oct Sat 18, 2014 8:16 pm
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Location: Galena, Ohio
But what about the older Zeniths from the late 20's and early 30's (37a, 39a, 40a, 54, 57) that had built in loop antennas? Were these just as good as the wave magnet antenna or is the concept different between the two?

The nice thing about these earlier sets is they did create a gear mechanism to rotate the loop antenna from the front of the radio.


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 Post subject: Re: Wavemagnets in Zenith Consoles
PostPosted: Dec Wed 06, 2017 6:15 pm 
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Joined: Dec Mon 08, 2008 8:27 pm
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Location: alameda,CA
GE made a number of consoles with large antenna "drums" in the back that you could rotate via a knob up front. I had one actually. It just used a simple pulley mechanism attached to a shaft which went through to the front of the set. I never used it though...


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 Post subject: Re: Wavemagnets in Zenith Consoles
PostPosted: Dec Wed 06, 2017 7:02 pm 
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Joined: Jan Mon 16, 2012 4:15 pm
Posts: 3619
Location: Near Brandon, Iowa
radios2100 wrote:
But what about the older Zeniths from the late 20's and early 30's (37a, 39a, 40a, 54, 57) that had built in loop antennas? Were these just as good as the wave magnet antenna or is the concept different between the two?

The nice thing about these earlier sets is they did create a gear mechanism to rotate the loop antenna from the front of the radio.

"As good as" is a subjective phrase. In terms of overall performance and waveband flexibility, the early TRF Zeniths were inferior to the later superhet, multiband sets. Did they point the way? Of course. Were they "Wavemagnets"? No.


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