Hi Guys,

I just acquired my first valve radio a Philips model 124 from an antiques dealer who was closing up! I was after any information on them. It will pick up local am but when switched to short wave or magnified band I get nothing. I am a complete newby in this field so please take it easy on me! Also what is the input plug on the rear of the unit? The dealer said he had his guy look over it and plugged it in to show me it worked. Thanks in advance!

I just looked at one of these on Ebay. If the input socket you describe is about 75mm away from the power cord entry then it looks like it is an input for a portable phonograph unit. Many radios from the 1940s had these sockets fitted and some had two-pin power outlet sockets fitted as well.

I am not sure what you mean by "magnified band" though with shortwave you aren't likely to pick anything up without a very long and high aerial and some radios require a good earth connection too (separate from the mains earth).

Magnified band may refer to a bandspread band. Similar to the old Astor radiograms.

I think "magnified" means bandspread tuning for the shortwave band. Only a decent antenna could pull in any usable shortwave signal.

Maven

http://item.mobileweb.ebay.com.au/viewitem?itemId=321125198712.

If you follow that link it shows the output I am referring to! Also one dial has the broadcast/shortwave and magnified band selection, thanks for the help guys

Yep, phonograph input.

Thanks a lot Brad and others, I have spent the whole night researching vavle radios my heads going to explode 😏 so could this input be used to hook up an external player? Like a iPhone and how would that input be selected to play in my radio?

I've thought long and hard about the idea of hooking up a modern player to a radio just to see what it would sound like. I've never really set aside time to see how it'd go though or even if our modern players would like being hooked up to their elderly brethren.

I suppose the only way to find out would be to try it but experimenting with a phone that is no longer used as a mainstream device would be the best way of going about it.

Also, I'd be 100% sure of what the socket is for first. It'd make sense if it was a phonograph input but it could have been booby-trapped by a previous owner to become an extension speaker socket, for example. If that is the case you definitely will not want to hook up a player to it. If you are new to vintage electronics you should get someone more experienced to double-check it first.

The shortwave bands given for the Philips 124 are:

9.4 MHz to 10 MHz (31 metres)
11.4 MHz to 12 MHz (25 meters)

and

5.9 MHz to 18.4 MHz ... quite a spread there.

It has a two-pin socket for gramophone pick-up.

Has anybody made a Am transmitter to plug into your phone similar to the fm ones you can buy so you can play your phone through your cars stereo? That was my original plan! I put the radio into our house a gea does it look amazing! I have brought a 1930"s home and am trying to bring back some charm from yesteryear! Previous owners had takin away some of the period features and now I am trying to bring them back!

My Philips 123 is same vintage, different model. The Pick-Up input is designed for the older generation of record players with magnetic pickups. These put out a higher current than modern pickups, but a lower current than a headphone output such as an iPhone, Ipod etc.

The PU input mixes automatically with the tuned AM radio signal. You "select" the PU signal simply by tuning your radio to an empty zone of the dial.

I have successfully attached component stereo devices and headphone outputs to the PU input (mono output, of course), but you may need a simple additional circuit to get a good quality impedance match. If you are lucky, you will be able to get reasonable quality just by adjusting the volume of the iPhone output for the best quality at low radio volume.

Here is an example of how to make a fairly sophisticated adaptor using the iPod dock adaptor:

http://antiqueradio.org/iPodAdaptor.htm.

There are simpler circuits as well that would use the headphone output - a single resistor may do the trick. Web search can be productive!

Maven

There are many low powered AM transmitters on the market. You can find them by doing a Google search. (Dont go for the expensive ones) These transmitters are designed to take input sources such as CD players & Ipods.

If you want to construct one yourself, Silicon Chip have a solid-state version designed by Jim Rowe.

http://archive.siliconchip.com.au/cms/A_105705/article.html.

Or you can do what I have done and that is to connect the output of a CD player directly into the phono input of a mantle radio. Works quite well on mine. Only thing you have to look out for is whether the phono input is designed for a magnetic of crystal/ceramic pick-up. Sets designed for crystal/ceramic pick-ups work the best.

Cheers

I've also tried plugging an audio source directly into the pu socket. It works quite well although as Brad suggests, not an expensive phone. The radio I used had a pu switch which isolates the audio section from the rf.

I've been looking at making an adapter with a couple of small audio coupling transformers , the secondaries wired in series. With the right impedance transformers it matches the input impedance, safely combines the stereo to mono and most importantly isolates the input from nasty voltages all in one passive unit. I've got all the bits for under $15 now I just need to get a "round tuit" which I haven't found yet

Warren

Scraps -

Could you post your adaptor circuit here? I for one could do with just what you describe.

In return, I could lend you my round tuit

Maven

I can't take credit for the circuit, just perseverance on Google.

http://antiqueradio.org/iPodAdaptor.htm.

I picked up the miniature transformers at Jaycar, I could dig out the part numbers if needed. I doubt the frequency response will be grand but it doesn't need to be.

Cheers,

Warren