Antique loop aerial, mains powered

[Gabe001]

Hi,

Coming across a couple of these antique, mains powered loop aerials (copper or aluminium) for sale, mainly from Europe.

Has anyone got one and can comment on whether they work or are likely to.

I do like the look of them and they would make a nice and potentially practical accessory but they don't come cheap though.

Gabriel

[Herald1360]

No reason why they shouldn't perform as well as one with a single transistor wideband amplifier. Maybe even better for intermodulation with strong signals.

A simple home built tuned loop would probably work just as well though you would have to use a two handed tuning technique to sweep across a band.

https://www.4mcveys.net/2018/10/05/a...am-broadcasts/

gives the general idea.

[Gabe001]

I'm afraid Mrs G will hang me from that frame if I bring that in the house!

Thanks for the info Chris. So what's the difference between the powered ones and the passive ones, performance-wise?
Gabriel

[rambo1152]

https://www.radiomuseum.org/r/socora...parasites.html

[Alvin]

I had one of these stylish French numbers several years ago but never got round to powering it up.
https://antiques-european-design.com...elard-in-1955/

[Herald1360]

Originally Posted by rambo1152

https://www.radiomuseum.org/r/socora...parasites.html

Interesting.....

It's a tuned amplifier, not a broadband one. The mysterious box in the circuit contains a selector switch and some coils and a capacitor (at least that's what's visible) for LW,MW and SW.

The circuit is clearly for a later model since it shows an EF80 with different resistor values from the unit in the pictures which uses an EF42.

Attached is "English style" version of circuit.

Assuming that the actual loop is a simple single turn of chromed tube it would make an interesting DiY project.

[Gabe001]

If you ever do test it let me know

Crossed posts this was meant for #5

[Gabe001]

Originally Posted by Herald1360

Interesting.....

It's a tuned amplifier, not a broadband one. The mysterious box in the circuit contains a selector switch and some coils and a capacitor (at least that's what's visible) for LW,MW and SW.

The circuit is clearly for a later model since it shows an EF80 with different resistor values from the unit in the pictures which uses an EF42.

Attached is "English style" version of circuit.

Assuming that the actual loop is a simple single turn of chromed tube it would make an interesting DiY project.

Nice work chris. I think I understand how it works now.
I believe there was a copper loop version and an aluminium loop version. The copper loop version allegedly performed better.
If someone here does make one, I'd be interested to know how it pans out.

Gabriel

[Julesomega]

To avoid the need to tune the loop while you tune the receiver you should use an untuned amplified loop like the one discussed in the thread MLA-30 Active loop antenna for valve radios

I was very pleased with mine when used outside with a larger single turn loop, but I've just tried it indoors with 5 turns of thick copper wire, dia about 8 in. This gives good reception of the local and semi-local MW and LW stations, as well as all SW bands. You would need to experiment with a step-up ferrite transformer

Should fit in your radio, and you'd need to find somewhere around 12V DC for it

[rojosuiza]

Those antennas are perfect for older tube radios - I have got 2 Belgian ITAX and 1 Swiss Komet, plus a gigantic passive SIEMENS one.

All of them give perfect results.

[Gabe001]

Thank you Julian and Rojo.
Julian I've had a read of the mla-30 thread and how to make the transformer and may give it a go when I have some time.

Rojo, when you say perfect results, does this mean pulling local and foreign stations on all wavebands without noise?

Gabriel

[Gabe001]

The ITAX looks great and is quite rare from what Ive read
Circuit diagram attached and good info on
https://www.vintageradio.nl/Diversen...nne_engels.htm

Gabriel

[rojosuiza]

Originally Posted by Gabe001

Rojo, when you say perfect results, does this mean pulling local and foreign stations on all wavebands without noise?

It fades out unwanted stations and reduces the noise. It pulls in only the wanted direction.

It is very much working like a ferrite-antenne in a sixties radio, but it is meant for tube-radios, without a built-in antenna.

[Gabe001]

Thank you