Best performing late 50s, valve, VHF radio?

[G8HQP Dave]

When growing up, the height of radio listening for me was a McMichael 255. This was in the front room so didn't often get used. It had a huge speaker in a largish cabinet so plenty of bass. Good reception on FM from the built-in antenna, although tuning was a bit fiddly - I now wonder if the discriminator electrolytic needed changing. My father bought the set not long after my parents married.

Day to day listening was AM on a much older set in the living room.

I still have the 255 and still hope to one day refurbish it.

[Pilot Mariner]

I have 2 Grundig 3028s and 2 Bush VHF64s, I think the VHF64s beat the 3028s in terms sound quality, the 3028s having a very "overblown" bass especially on VHF. My Murphy A574s sound very good mainly due to the huge plessey speaker and feedback networks. I also have 3 hacker mayflowers patiently waiting restoration so can't comment on them just yet.

[Peter.N.]

I think I was earning £5.00 per week when we were selling the VHF64. On the subject of age and high frequency response I have found that although mine has dropped of it is still there given sufficient volume.

Sitting close to the computer sound system or the car radio I can still hear '50s hits as I remember them. There are a number of hearing tests on you tube and if I turn my head in the right direction I can still hear up to 9khz or maybe a little higher and I am 80 years young - but I can't hear what my wife is saying.

Peter

[stevehertz]

Indeed Peter. All you have to do is address your HF drop off by judicious use of the treble control until (say) the cymbals are to your liking or as you recall it. That's why I can't get my head around the purist attitude of some hifi enthusiasts who seem to think that the omission of tone controls enhances the sound to a greater degree than an actual heard decent frequency response.

[Hybrid tellies]

A spanner in the works and possibly off topic, but back in the 1970's my brother was given this late 1950's rather large Dynatron 405 line only television with built in VHF/FM tuner with just three presets Light, Third and Home. Where we lived in west Cornwall FM reception was not good and most VHF/FM radios, valved and transistor, all struggled. Not so with this Dynatron it pulled in all three BBC stations with no background hiss or any other form of interference, not a sign of multipath distortion or any fading effects from the helicopters from the nearby RNAS Culdrose base. All just using a few feet of wire as an aerial strung across our bedroom. The sound quality from the fairly large speaker was excellent with plenty of volume and no distortion at high levels of volume. A few years later I had a similar performance from a smaller late 1950's 19" 405 only Bush television set. To me it proved how well a VHF/FM radio should work using a good front end tuner with a separate RF amp as found in most televisions. It was a hard act to follow not equalled by any of the VHF/FM table radios of the day.

[stevehertz]

Dynatron was Hacker and of course the latter a great performer.

[Hartley118]

I wonder whether UK VHF sets used a rather idealistic front-end designed specifically for an external dipole aerial and 75-ohm feeder. Certainly my Hacker Mayflower 1 is configured that way: the 'electrically short' internal aerial with its inevitably high source impedance simply feeds into that 75 ohm input. It works reasonably well, but I feel it could be more sensitive.

On the other hand, car radios have over recent years been progressively optimised for their electrically short aerials with high impedance matched aerial preamps to the extent that they work remarkably well with an aerial that is merely a slight bulge in the roofline.

Do we have any evidence that 1950s continental VHF radio design took more care than UK design over internal aerial impedance matching?

Martin

[MurphyNut]

Originally Posted by stevehertz

Indeed Peter. All you have to do is address your HF drop off by judicious use of the treble control until (say) the cymbals are to your liking or as you recall it. That's why I can't get my head around the purist attitude of some hifi enthusiasts who seem to think that the omission of tone controls enhances the sound to a greater degree than an actual heard decent frequency response.

I rather like equipment that doesn't give you the temptation to mess about with the frequency response. If you have a quality setup with a decent recording, tone controls are unnecessary.
I've had systems in the past with all sorts of filters including the dreaded "graphic equalizer" and realized I was spending more time fiddling about with the controls than actually listening to the music.

[Nuvistor]

Originally Posted by Hartley118

Do we have any evidence that 1950s continental VHF radio design took more care than UK design over internal aerial impedance matching?

Martin

They tended to use 240 ohm aerial impedance, whether this helped with the internal wire dipoles I don’t know.

[Nuvistor]

Originally Posted by MurphyNut

I rather like equipment that doesn't give you the temptation to mess about with the frequency response. If you have a quality setup with a decent recording, tone controls are unnecessary.
.

My hearing drops off rapidly in one ear at around 4khz and the other around 8khz, without a tone control I would miss much of the music but I don’t fiddle with the setup, once set it gets left alone.

[simpsons]

Should your hearing no longer reach 7kHz or above, this will have the same effect as, subjectively, an over bass response when listening to a receiver. This can of course be adjusted out if suitable equalisation is available.

The Bush has according to the BBC R&D report inherent loudness compensation with a peak at 100Hz and 10kHz and because of the effect on the negative feedback circuit, different turnover frequencies as the bass and top cut controls interelate with each other.

The grundig is quite diffrent as the tone controls are bass cut, then boost/cut with turnover frequencies at 1.8kHz, 2.6kHz and approximately 10kHz. The Grundig, although it does have have side facing mid/tweeters to give it the so called 3D sound, the main speaker is mounted off centre to reduce colouring the sound with peaks and troughs.

In both the Bush and Grundig, the low frequency response is also improved by having a rim around the front of the receivers.

[G6Tanuki]

Originally Posted by Hartley118

I wonder whether UK VHF sets used a rather idealistic front-end designed specifically for an external dipole aerial and 75-ohm feeder. Certainly my Hacker Mayflower 1 is configured that way: the 'electrically short' internal aerial with its inevitably high source impedance simply feeds into that 75 ohm input. It works reasonably well, but I feel it could be more sensitive.

I recall at least one UK VHF receiver whose internal 'stapled-to-the-back-cover' dipole included loading-coils so it was vaguely-resonant and presented a more-sane impedance to the first RF circuit.

Equally, there's a comment in "The Setmakers" that UK designers expected their 1950s/early-60s FM radios to be fed from an external rooftop antenna and that when people used 'rabbit-ears' or the silver-foil built-in antennas and complained about the rattly distortion/sibilance caused by the multipath distortion which resulted, the retailers said that they were just hearing what the BBC was transmitting!

I've always considered a proper outdoor multi-element directional antenna (preferably with a rotator) to be the essential starting-point for good FM reception. OK, a bit-of-wire down the back of the receiver can sort-of work for really-local stations.... but it lacks ambition.

[stevehertz]

Originally Posted by MurphyNut

I rather like equipment that doesn't give you the temptation to mess about with the frequency response. If you have a quality setup with a decent recording, tone controls are unnecessary.
I've had systems in the past with all sorts of filters including the dreaded "graphic equalizer" and realized I was spending more time fiddling about with the controls than actually listening to the music.

We have to agree to disagree on that one. If only it was that simple. The fact is, the many thousands of recording studios around the world including all the ones no longer in existence, do not have playback/monitoring systems that correlate frequency response wise. So, a recording made at one studio, may (quite possibly), on someone else's system sound very different. When I've put forward this argument to people in the past, their response has been to say, "Well I'm listening to what the producer wanted". Er... NOT! You are listening to what that 'mix' sounds like on YOUR playback system, NOT as was heard and intended to be listened to by others when the producer and/or mixdown engineers or artists created the final mix in the studio. So, on that basis, that very few recording studios have playback systems that sound the same, and more often than not different from our own, then we, the recipients of these slightly 'off' recordings (or owners of slightly off playback systems and rooms) need to tweak a tone control or two to correct for system disparities. Probably because I'm a musician I can't stand listening to a recording that is lacking in or has too much bass or treble. A few seconds adjustment is all that is required, it's not a problem, and yes, it is quite likely to need to be adjusted for each 'record'.

[G8HQP Dave]

The internal VHF antenna would often be a folded dipole made out of 300 ohm twin feeder. If straight this would present an impedance around 300 ohms. In many cases the ends were bent to fit the cabinet so the impedance would be smaller.

[Valvepower]

Hello,

Seeing this thread reminded of a report, which was done by the BBC R&D department in the 1950’s on the Murphy A242, which I've attached (this PDF is also available on their web site).

This showed the BBC took the quality of the VHF radios seriously.

Regards
Terry

[simpsons]

Thank you Terry for illustrating the BBC R&D review of the Murphy A242 and especially how the audio response has been shown, from the external speaker socket, not of course how it sounds from the loudspeaker.

When a recording studio is mixing down from 10, 20, it doesn’t matter - microphones or other audio sources –to record for cd, digital domain or vinyl reproduction, the recording will be played back on far field or near field monitor loudspeakers and the master will be tailored to the artists/producers requirements.

At home, it’s a different matter. The recording will played back on a domestic radio of wildly varying quality or it could be a pair of Quad ESL63, I wish, or maybe a music centre; the recording studio has no control on this. The listener has what they have.

The room they are listening in, the loudspeaker used, their perceived preference and so on, will influence how they believe the sound quality of their kit is so much better than the guy next door.

Oh for the days of Gordon J King whose articles and reports were designed for those who understood what was in front of them. His reports on audio, video and so on were illustrated by frequency response curves, dB’s and RMS. None of the warm, crystal clear, fast attack etc. etc; or subjective sound quality based on a particular cd without any reference to the room or radiation domain or environment, so important when measuring or listening to sound.

His reports were written for the technically adept. Today most readers of HiFi News or whatever would have no idea or the skill to interpret such reports which is why it’s all about how good a particular cd sounded and nothing about sound quality.

[Murphy Maniac]

For me, it is no contest. Of all the radios I own, and that's quite a lot, the best VHF performer overall has to be my Murphy A272C. Clarity across the audio frequency range is excellent with a solid bass foundation, and not the slightest hint of booming or resonance. There is absolutely no trace of tuning drift.

[simpsons]

Thank you Geoff for nominating what is an iconic design. There have been several threads on this and the 146C and I did once (as a youth, oh so long ago) have a large unsealed infinate baffle set up in my bedroom or as I knew it then as a large board with a speaker in the middle!

Whilst the rest of the family made do with a KB toaster, this set up sounded the dogs biscuit. It was fed by a Philips EL6415 amplifier, which had come my way, fronted by a home made FM tuner which drifted off tune quite a lot!!