Dear Colleagues,

Can anyone identify this set ? It is part of a stereo radiogram and I can't find a model number anywhere on the cabinet or chassis. The set simply has "Dual" on the front panel. It has a separate AM and FM tuner, which can be played independently through each stereo channel.

Attachments

• Pilot Radiogram Console 1 (100 KB)
• Pilot Stereo Radiogram Console Rear (115 KB)
• Pilot Stereo Radiogram Underneath (102 KB)

Dear Bryce
I try to bring the subject up again.

It looks quite unusual for me with this left part on it.
Can you - after some days without answer - bring also a picture of the cabinet?
Is it definitely made by the British Pilot?
It seems to have 10 tubes. Can you list them?
Who made the filters? (Philips alike?)

Thanks Ernst,

The owner has now sent me pictures of the complete radiogram. The valve line-up is as follows:-

FM Section:

ECC85, EF80, EF80 germanium diode discriminator.

AM Section

ECH81, EC91 , EBF89 - purpose of the triode is unknown - maybe an oscillator buffer, or maybe the local oscillator.

Audio ECC83, EL84 x2 (One for each channel)

Rect EZ81 Tuning Indicator EM84

IF Transformers were almost certainly Philips (Those tiny ones that have a bit of ferrite stuck to a brass ferrule. This falls of causing all sorts of amusing faults. In this case, the set would only play when upside-down.)  This set allows you to play AM through the right speaker, whilst listening to FM or Gram on the left. Gramophone pick-up is crystal pick-up. Deck is Garrard. 

I deeply suspect that this is a South-African model. Pilot seems to have been a popular make here, judging by the enquiries I get, but I don't know the history of Pilot in South Africa. Something to research.

- Bryce

Attachments

• Cabinet with drawers closed (57 KB)
• Cabinet open, showing Garrard deck (55 KB)

There is some similarity with PYE radiogram VHF3DSG. It only lacks the EC91, but uses a Garrard record changer and,

To search in that direction needs some investigation of the hardware, to compare with said Pye set (or others).

I could imagine that Pilot is the model name (relabeled from a PYE model), not the manufacturer.

I hate reading tea leaves, but that is currently the best I can offer.

Good luck!
KoBi

Thanks Kobi,

The model certainly could be a re-brand of some other well-known manufacturer's model. It certainly is a 'Pilot' with the seafaring logo and the (all - original) knobs have the helmsman's wheel painted on them. The PYE radio is somewhat more conventional, because I see that it has a common IF stage for AM and FM in the detector. In the Pilot "Dual" they are kept entirely separate all the way (which is why you can oddly play AM through the left channel and FM through the right).

I now regret not tracing the circuit of the EC91 / ECH81 combination - maybe I'll get an opportunity as I have just received some new valves for the owner.

I really would like to have this in the museum. By the way - I assume I am correct in saying the radios are not in my collection when I photograph someone else's set? - as is the case here.

Regards - Bryce

Prior to introduction of multiplex stereo on a single VHF frequency, there had been attempts to use separate frequencies even in different bands (e.g. BC and VHF) for the stereo channels.

The independent simultaneous operation in AM and FM of a.m. Pilot Dual receiver looks like being made for that.

Who can shed some light on the matter of split/dual stereo? Where? When? How? 

KoBi

Regarding early stereo reception you find informations here. This thread links also to an extensive german contribution by Prof. Dr. Rudolph. Joe Sousa found something about CBS Simplex Stereo.

Radios with two separate AM sections was made by Pioneer:

One example is model SMG-204 with it's two magic eyes. The AM sections are different: one is for BC/SW as usual, the other one for FM/BC is switchable from "Soft" to "HiFi" for the AM section. For FM stereo a separate decoder must be connected to "MPX out". It receives FM from 80 to 108 mc.

Similar models are SMQ-140,SMB-200, SMB-200A and SMQ-300.

Best Regards,

GR

Dear Colleagues,

Just had my memory jogged by Chas E Miller's book. The BBC used to transmit one channel on the TV1 sound channel (Band 1 41.5 to 63.25 MHz) and FM (Radio 3 - the "Highbrow" channel) for the other. FM was introduced in the UK in 1955 according to the same source. Stereo transmission in the USA seems to have been ratified by the FCC in 1962. In South Africa, we had to wait until the mid-70s, with many radios having the stereo facility but nothing to decode. I remember the sense of wonder when the stereo pilot light on my Marantz came on for the first time.  Miller's  book has two circuits for valve pilot tone stereo decoders.

This points to the "Dual" idea in this set being there to allow listening to different stations in different rooms.

- Bryce

Ref: Chas.E.Miller Practical Handbook of Valve Radio Repair - Newnes