Things you're glad you didn't buy.

[DrStrangelove]

Inspired by the Technics SEA-1 thread.

The Yamaha B2 C2 combination.

No doubt it sounded lovely until the Total Unobtainium SITs turned their toes up.

The B1 amplifier even more so.

[Beobloke]

Ah yes, the VFET - as a friend puts it - "Very Fragile; Expect Trouble"!

Then again, my own Yamaha B2 was very reliable and sounded superb when I owned it. Admittedly, all the VFET circuitry had been ripped out and replaced by two Hitachi MOSFET power amplifier modules, but still...

[Wendymott]

In the early 70's I nearly bought a HP spectrum analyser... not sure of the model it was that Dual beast with a seperate display. It was for sale at £100 in an Ex gov shop in Leeds on Meadow Lane.. I think the shop was JT Supply.. I was working at the UOB "Bradford University" Physics dept, and I mentioned it to a colleague in Elec eng. I was told in no circumstances to buy it as the TWT oscillator, if faulty would cost over £1000 to replace. Lucky escape.. I had to wait for several years to obtain my Thandar "add on" box.

[Doghouse Riley]

I've read various criticisms of Yamaha products, which surprises me, as I've been playing Yamaha electric pianos for forty years, I've traded up over that time, currently playing a Tyros 5 which I've had for six years, before that it was a PSR1000 which I had for twenty years, none of them have ever had a fault.

[DrStrangelove]

As the proud owner of a Yamaha CT7000 tuner (£450 in 1977), I was infinitely impressed to find that some of the tants were in back to front.

They produced an odd rumbling sound which went away when I replaced them with film capacitors.

[factory]

Originally Posted by Wendymott

In the early 70's I nearly bought a HP spectrum analyser... not sure of the model it was that Dual beast with a seperate display. It was for sale at £100 in an Ex gov shop in Leeds on Meadow Lane.. I think the shop was JT Supply.. I was working at the UOB "Bradford University" Physics dept, and I mentioned it to a colleague in Elec eng. I was told in no circumstances to buy it as the TWT oscillator, if faulty would cost over £1000 to replace. Lucky escape.. I had to wait for several years to obtain my Thandar "add on" box.

Almost certainly the HP 8551/851 spectrum analyzer.

https://www.hpmemoryproject.org/time.../hp8551_01.htm

David

[Cruisin Marine]

Yeah, almost certainly was. I called them "Washing Machines" 'cos they looked like one.

I had two units, one good and one bad (Travelling Wave Tube had almost expired, but I got it cheap for spares).

They performed very well when working.
The TWT looked just like a black house brick.

Back in the day, they were something of a luxury.

[Joe_Lorenz]

Glad I didn't buy a Sinclair ZX 81 back in the days. Coming from Zuse Z 25 learning "Algol" language I was just about to get a Sinclair well before they would have been readily available here on the continent.
My wife convinced me to wait instead some more months for the brand new Commodore 64 to arrive - no bad decision, after all. I was very happy with it!

Joe

[slidertogrid]

Any Ferguson TVs after they were made by Thompson !

[Red to black]

Now, now! ha ha

[jamesperrett]

I was reminded the other day that there once was a company called Studio Magnetics who made tape machines (they were associated with ACES). Back in the day I was looking at one of their narrow gauge multitrack machines to upgrade the studio from 8 to 16 tracks. I'm glad I went for a Fostex instead because it was only later that I learned how unreliable the Studio Magnetics / ACES machines actually were.

[knobtwiddler]

I remember seeing the dealer listings for the Aces machines as well. They were a mere fraction of the price of other recorders and I was always suspicious. Were they related to the Soundcraft machines? (Soundcraft were what became of Brenell, I believe). The Soundcraft had a terrible reputation and were regarded as under-developed (unlike the mixers, which I have always held in decent regard in terms of cost / performance ratio).

[m0cemdave]

Originally Posted by knobtwiddler

I remember seeing the dealer listings for the Aces machines as well. They were a mere fraction of the price of other recorders and I was always suspicious. Were they related to the Soundcraft machines? (Soundcraft were what became of Brenell, I believe). The Soundcraft had a terrible reputation and were regarded as under-developed (unlike the mixers, which I have always held in decent regard in terms of cost / performance ratio).

The few items of ACES equipment I encountered (never met any of their tape machines but would have avoided like the plague) were appallingly horrible in both design and manufacture...

I did use a couple of Soundcraft multitracks and they worked OK but these were in budget / musician studios where they didn't get the heavy use typical of a commercial facility. And I recall having to fix a power supply in a 2400 where the solder joints on the pass transistors (or were they regulators? long time ago) had failed, the PCB holes were much too big for the TO3 pins.

A sometime colleague of mine was chief engineer in a well-known studio that had acquired a couple of the early Soundcraft 2400s. They had so much trouble with them that the company had to take them back - and supplied a couple of machines from a competitor (Otari I think) as a "goodwill gesture" presumably to keep the owners, a couple of very well known musicians, quiet...

[jamesperrett]

The Soundcraft machines have a much better reputation than the Aces machines amongst the technicians that I know who have worked on both. Superficially they look very similar with all the audio channels in rows below the transport but I don't think they have much in common. I've recently seen a manual for the Studio Magnetics/ACES 24 track machine and the design is about as basic as possible for such a machine. Certainly the Fostex E-16 is a much more sophisticated beast - even though it is much smaller and cost less to buy at the time.

I've just downloaded a manual for the Soundcraft and it is more sophisticated than the ACES although nothing like as sophisticated as the Otari MTR90.

[Craig Sawyers]

Originally Posted by factory

Almost certainly the HP 8551/851 spectrum analyzer.

https://www.hpmemoryproject.org/time.../hp8551_01.htm

David

Odd that TWT's are seen as flakey and with limited life in test equipment. They are in every satellite - certainly interplanetary ones - and are the core microwave generators responsible for comms to earth. They work for decades. The longest lasting ones are on Voyager 1 and 2, and they are still working just fine and sending data back to earth 46 years later. 23W transmitter power from nearly a light day distant.

Craig

[Radio Wrangler]

I think it would have been a BWO as the LO, not a TWT in that instrument. They were certainly BWOs in the sweepers of that era.

Mind you, look at the prices of new YIGs

David

[fetteler]

Originally Posted by Craig Sawyers

...They are in every satellite - certainly interplanetary ones ...

Craig

Errr... if it's interplanetary then it's not a satellite I'm afraid.
Please excuse my pedantry but I cant help myself

Steve.

PS I'll get my coat...

[Welsh Anorak]

Back to Sir Clive I almost bought a Sinclair QL in the OPD (one per desk) guise. A great idea, as usual, let down by those hopeless tape drives.

[jimscoper]

Once bought an old EIP heterodyne counter. Think RTL logic and nixies. The 1Ghz range did not work. Delving revealed some clumsy work around the 1G YIG filter. Long story short the YIG sphere had come off its post. Incoming hard coax had been badly bent and broken. Found sphere - about 0.2mm dia. But tweezers went twang and the sphere went flying. Never seen despite strenuous efforts. NBG but the 18GHz YIG was OK and the 100MHz was OK.

Another not so good was a 8558 HP spec analyser with display. Something bad had happened to the +15 volt regulator, 15 volts was now 100 but the plug in was saved by hefty zeners on the incoming rails. Fixed all that to discover the storage tube was a bit weak and a fair number of the switching combs from the plugin were missing (not rattling around the case). A bit of lathe work and fancy metalwork fixed that. Some plain and fancy tube restoration did a little bit of good. In the end a fairly good analyser but a PIA to use.

[factory]

Originally Posted by Radio Wrangler

I think it would have been a BWO as the LO, not a TWT in that instrument. They were certainly BWOs in the sweepers of that era.

Mind you, look at the prices of new YIGs

David

The 8551B manual is on the web, it does have a BWO.
TWTs were used in the high frequency amplifiers from HP.

David