Test Equipment Anonymous (TEA) : Discussion and Group Therapy Thread

[tggzzz]

I'm selling/have been trying to sell an Aerialite TV signal booster.

Relist it, but mark it as "rare, valve/tube, audiophile" - with an increased price, of course.

[Zenith]

I'm selling/have been trying to sell an Aerialite TV signal booster.

Relist it, but mark it as "rare, valve/tube, audiophile" - with an increased price, of course.

Maybe, but the valves in it are likely to be ones you'd find in a 1950s TV and designed for VHF, so not on the valve audio shopping list. Most telly valves have never been worth much. It's really something only likely to appeal to the vintage TV crowd, and even then as something of a curiosity. People interested in 405 line sets have long invested in standards converters. Analogue TV has been dead for some years.

Two of the valves in the photo are Mazda 30L1.

http://www.r-type.org/exhib/aaq0066.htm

A double triode designed for cascode use at VHF and with a 7 Volt heater (300mA), which fits with the 7.3 Volt winding of the transformer. Quite likely to be highly microphonic and very noisy at audio.

In the 50s a lot of areas were marginal for BBC TV. ITV came out and the transmitters were fewer and less powerful, hence the market for signal booster amplifiers. I believe some early sets could only receive BBC, hence signal booster type boxes that could tune either BBC or ITV at the flick of a switch. The ones I've seen were in a metal case about 12" x 4" x 4". The one I took to bits was made by Advance. There were solid state mast head amplifiers in the early 60s. They may have used similar things in TV showrooms and blocks of flats, to avoid having lots of aerials.

[tggzzz]

... which is all rational, and therefore is orthogonal to the audiophile market

Hells teeth, I long long ago heard the comment that if a luxury item isn't selling, take it off the market and put it back on the market at twice the price.

[Zenith]

The valve audio market is silly, but not indiscriminately silly. It follows fads and fancies which are subjective, and dubious on any rational or engineering basis, but they are not willing to snap up any old valve for outrageous prices. Telly valves with odd heater voltages and intended for VHF use in TVs are of no interest to them.

I remember the headmaster giving a talk on how high prices are linked with quality. He mentioned an experiment done in Canada where a hardware store was given a number of identical coal scuttles. They put them in two groups, one lot priced at $3 and the other at $6. If asked they were to say there was absolutely no difference between them. The $6 scuttles sold out much faster.

He had a friend who owned a chain of clothes shops and came by a consignment of sweaters. They were about the best quality he'd seen and were ridiculously cheap. He had them on sale for 50p each. In weeks hardly any sold. He put up the price to £5 and they'd all gone within days.

[MED6753]

I have a question for you learned engineers. Riddle me this...

On some of the streaming services that Blondie watches many times the audio and video are out of sync. The audio delays a second or two. But interestingly the audio and video on the commercials on the same service are in sync. The internet here is 400Mps and the TV in question is hard wired CAT5 to the modem so that rules out any WiFi issues. Any ideas why this is happening and can anything be done to rectify it?

[mansaxel]

I'm selling/have been trying to sell an Aerialite TV signal booster.

Relist it, but mark it as "rare, valve/tube, audiophile" - with an increased price, of course.

Maybe, but the valves in it are likely to be ones you'd find in a 1950s TV and designed for VHF, so not on the valve audio shopping list. Most telly valves have never been worth much. It's really something only likely to appeal to the vintage TV crowd, and even then as something of a curiosity. People interested in 405 line sets have long invested in standards converters. Analogue TV has been dead for some years.

The Brimar / British Valve Project people have made a "TV amp" that aims to use just those valves for AF amplification. It apparently can be done, but of course would require some effort and adaptations.

[Zenith]

I have a question for you learned engineers. Riddle me this...

On some of the streaming services that Blondie watches many times the audio and video are out of sync. The audio delays a second or two. But interestingly the audio and video on the commercials on the same service are in sync. The internet here is 400Mps and the TV in question is hard wired CAT5 to the modem so that rules out any WiFi issues. Any ideas why this is happening and can anything be done to rectify it?

No specific suggestions, but you might have a look through this.

https://www.anyrecover.com/file-repair/ ... t-of-sync/

Found by searching on "audio and video out of sync streaming service".

It's striking that the commercials are always in sync.

After checking the basic things, such as whether the cables are up to snuff and the firmware in the TV is up to date, take it up with the streaming service.

[Zenith]

The Brimar / British Valve Project people have made a "TV amp" that aims to use just those valves for AF amplification. It apparently can be done, but of course would require some effort and adaptations.

I couldn't find any mention of it on their website.

https://brimaruk.com/

It seems to be a cooperative venture to make valves in the UK and they offer a few valves, which are the usual audio types you'd expect to find in audio amplifiers built in the 50s and 60s. If that's what people want to do, that's a matter for them.

All sorts of valves never intended for audio have been adopted. ECC88 (6DJ8), which was a high gain double triode intended for use in wide band amplifiers, was discovered about 25 years back, and prices shot up. Valve scopes were full of them. They were never used in audio amps back in the day. E88CC (6922) was a special quality version with gold plated pins. Gold plated pins obviously count towards sound quality. It was intended for computers. The gold pins were to avoid contact problems, which were a problem when thousands of valves were used. Most special quality valves were ruggedised. This had special cathodes, which could withstand prolonged use with no cathode current, without being poisoned and losing emission.

[mansaxel]

I have a question for you learned engineers. Riddle me this...

On some of the streaming services that Blondie watches many times the audio and video are out of sync. The audio delays a second or two. But interestingly the audio and video on the commercials on the same service are in sync. The internet here is 400Mps and the TV in question is hard wired CAT5 to the modem so that rules out any WiFi issues. Any ideas why this is happening and can anything be done to rectify it?

There are many sources for sync loss. Main reasons are decoding time for various compressed formats, and forward error correction related buffering delays. Those can be compensated for in the playout/continuity (at the TV company) to some extent, but there are always some things that can't be foreseen. In the case of syndicated content, there are risks as the programming is synthesised at a late stage. In case of streaming, the ad/content mix may well be spliced together in the set top box, which opens a full case of worms, mostly related to how the media streams are delivered, and the time required to unpack the various stream components. For instance, ads can be stereo, but movie mixed in surround, giving different decoding times.

[mansaxel]

The Brimar / British Valve Project people have made a "TV amp" that aims to use just those valves for AF amplification. It apparently can be done, but of course would require some effort and adaptations.

I couldn't find any mention of it on their website.

http://www.tellytone.com

[Zenith]

The Brimar / British Valve Project people have made a "TV amp" that aims to use just those valves for AF amplification. It apparently can be done, but of course would require some effort and adaptations.

I couldn't find any mention of it on their website.

http://www.tellytone.com

It seems to be a guitar amplifier with curious styling. No mention I saw of 30L1/7AN7/PCC84, but I didn't look that closely. No silicon in the signal path, which is self-evidently a GOOD THING. Guitar amplifiers were interesting and the overload characteristics and 2nd order distortion were considered part of the sound. The muddy tones of the Orange, the subtlety of the Vox, the definite but not overly assertive harmonic complexity of the Marshall.........

[mansaxel]

It seems to be a guitar amplifier with curious styling. No mention I saw of 30L1/7AN7/PCC84, but I didn't look that closely. No silicon in the signal path, which is self-evidently a GOOD THING. Guitar amplifiers were interesting and the overload characteristics and 2nd order distortion were considered part of the sound. The muddy tones of the Orange, the subtlety of the Vox, the definite but not overly assertive harmonic complexity of the Marshall.........

I will admit to not having looked so closely either, but, in the Brimar shop, which is colocated and where there's a listing for the Tellytone, they mention the valve equipment thusly: " The amazing sound comes from the Brimar Tubes more traditionally used in other applications." which given the styling of the box leads the lively mind into speculation in a certain direction.

Also, there is a review in Sound on Sound, that gives some more detail on the setup and mentions a few of the valve types, but it's not much more.

[bd139]

People will buy anything these days

[AVGresponding]

I'm selling/have been trying to sell an Aerialite TV signal booster.

Relist it, but mark it as "rare, valve/tube, audiophile" - with an increased price, of course.

Maybe, but the valves in it are likely to be ones you'd find in a 1950s TV and designed for VHF, so not on the valve audio shopping list. Most telly valves have never been worth much. It's really something only likely to appeal to the vintage TV crowd, and even then as something of a curiosity. People interested in 405 line sets have long invested in standards converters. Analogue TV has been dead for some years.

Two of the valves in the photo are Mazda 30L1.

http://www.r-type.org/exhib/aaq0066.htm

A double triode designed for cascode use at VHF and with a 7 Volt heater (300mA), which fits with the 7.3 Volt winding of the transformer. Quite likely to be highly microphonic and very noisy at audio.

In the 50s a lot of areas were marginal for BBC TV. ITV came out and the transmitters were fewer and less powerful, hence the market for signal booster amplifiers. I believe some early sets could only receive BBC, hence signal booster type boxes that could tune either BBC or ITV at the flick of a switch. The ones I've seen were in a metal case about 12" x 4" x 4". The one I took to bits was made by Advance. There were solid state mast head amplifiers in the early 60s. They may have used similar things in TV showrooms and blocks of flats, to avoid having lots of aerials.

Yeah, all three are the same, but the markings are a bit worn on one of them. Mazda 30L1's are easily found for a £/$/€, so not really rare or valuable.

[tggzzz]

People will buy anything these days

'Twas ever thus Or perhaps

[Zenith]

People will buy anything these days

That must be it. For about that price you can buy new, a guitar amplifier from a recognised maker that's been in business for years, and will very likely have a better value on the used market, should you choose to sell it.

https://www.andertons.co.uk/browse/amps/valve-amps/

Then of course you could looked at the second hand market first.