New gear

[joebog1]

I guess sometimes things happen in the right way.
Yesterday I was given this lot of clobber. I will be refurbishing most of it in the next weeks.

Joe

[Radio Wrangler]

Rather a nice gift. From the era when things were beautifully made.

David

[Craig Sawyers]

Great gear. The HP distortion analyzer was the standard piece of kit used in audio development. I used to have one, until I nailed a Tektronix AA501 for USD14 on BIN on eBay.

I still have that signal generator though. Manual for that is here http://www.hparchive.com/Manuals/HP-...ual-sn-818.pdf

[David Simpson]

Joe, that's a dream collection. Many of us will be very envious. It looks in mint condition.

Regards, David

[turretslug]

Very nice bag of gear there you got there Joe- even when things like that need mending/overhaul, the standard of construction can turn a chore into appreciation and something of a pleasure!

Colin

[Electronpusher0]

Very nice!
I have the same Distortion Analyser, I have the manual if you need it, too big to post so send me PM with and e-mail address if you would like it.

Peter

[factory]

Nice gift, I wonder if the 403B AC voltmeter, 209A oscillator & 350D attenuator set were in one of those combining cases, the lack of feet makes me think they may have been.

Hopefully the rechargeable batteries in the 403B haven't leaked.
Those 209A don't seem very common (I'm still looking for a decent one), they are a nice & compact sine/square wave oscillator.

The 1960's 334A, just to let you know certain serial numbers of these 33xA series distortion analyzers with the PH-163 connector have the ground/earth pin connected via either an inductor or resistor to the outside case, more info in this thread;
https://www.vintage-radio.net/forum/....php?p=1188861

David

[joebog1]

Initial viewing inside the oscillator and attenuator is a bit scary. The switch brackets have thick corrosion fur all over them that's not easy to remove. I don't know if they were swimmers after a storm, or it's from being stored in less than ideal conditions.

Has anybody seen this before in these instruments? I have yet to look at the voltmeter and distortion analyser. I know why most of the knobs are broken, by forcing the totally seized shafts!!!

I will keep you posted.

Joe

[joebog1]

Well, seems it was too good a deal!!!
I think these deep diving pieces of equipment MIGHT provide the odd resistor if that. Definitely been to the bottom of the Gulf of Mexico, where it was allowed to soak for some time. The pieces cost me nothing, but there is not much left.
My friend bought them in good faith but got ripped!!. A warning to you all.

I have taken the covers off the voltmeter, which is where the "switch" pic is from. It's literally WELDED together with what I would suggest, is salt water damage.

The meter movements still "swing" left to right and I cannot "see" any corrosion. If any member needs bits, will cost you the postage.
These pieces are a few parts only for recovery.

I still have to strip naked, one 334A distorted meter!

Joe

[Diabolical Artificer]

Check the lamps in the metal box that form part of the auto circuit Joe, in mine the foam had deteriorated and eaten through one of the legs of the lamp.

Andy

[Silicon]

That white corrosion may not be as bad as it looks.

If it is 'white rust' it could be corrosion of the zinc plating.

It has a volume 100 times greater than the zinc consumed.

The metal underneath may be discoloured but still functional.

[Diabolical Artificer]

That's a bummer Joe, still a good clean might sort it. To clarify I'm on about the HP 334A in my last post # 10..

Andy.

[factory]

If I find corrosion on the inside then it's usually corroded on the outside too (units with leaked batteries can have corrosion on the inside only), but those look clean on the outside.

The shafts are often hard to turn or seized from dried out grease.

David

[joebog1]

Oh joy of joys!!! I opened the distortion analyser and it is in pristine condition. Absolutely brand new ( ooking). So all is not lost. It is a little scary though with hundreds of capacitors that I hope won't need changing.

Joe

[dave cox]

HP didn't use cheap capacitors, they might even be wet tantalum.

dc

[turretslug]

Ha, you've got us drooling there Joe, that old HP construction is delightful.

Fingers crossed that the other stuff is actually salvageable, I have in the past resorted to the careful use of engine valve spring compressors to free seized rotary switch shafts (circlips etc. removed of course!) and it worked well

[Radio Wrangler]

The pcbs will be nickel plate and pretty tough. They had to be soldered with a foaming acid flux immediately before the solder wave, then washed off immediately after. Hand-loading and soldering a new board of this type was a bit of a pain.

I think those are aluminium electrolytics.

HP later used a lot of wet tants. If any need replacing now, the prices are fearsome. One for my 8566B is going to cost 81 quid (single price, Farnell)

David

[factory]

Originally Posted by dave cox

HP didn't use cheap capacitors, they might even be wet tantalum.

dc

There maybe a few Solid Tants (Sprague 150D) in the 334A, the problem ones are Sprague 109D wet tants, which leak & rot away after several decades (even if not used), I can't see any of those in the parts list.

David

[cmjones01]

I recently restored a 334A (the link posted above is part of the story) and not a single component needed replacing, even though it looked like it hadn't been used for years and years. A little contact cleaner and a rebuilt meter scale and it met its calibration spec without any adjustments.

Don't worry about the capacitors. You can probably just switch it on and start using it!

One odd thing about the 334A, if anyone cares: the meter's frequency response is a bit odd. When adjusted according to the calibration instructions, it ends up with a rising frequency response peaking at about 12MHz, except on the most sensitive range when it rolls off sooner, without the peak. This can give confusing results when you're measuring the distortion of a signal containing high frequency (>1MHz) harmonics or noise. Switching down to the 0.1% range appears to suddenly improve the measured distortion.

Chris

[joebog1]

Thanks cmjones!!
I feel a bit better. There is one thing I will do, and that is change that horrible mains plug on the back panel. I dont know why, but all the mains leads I received with this stuff is gluey and sticky.
That way I can fit new IEC mains cables. I have a few bits of HP test equipment, but none have that plug. In fact most have captive cables. Captive only because Australian 3 pin plugs are too large to fit thru the hole designed for US ( probably) 2 pin 110 volt plugs. I have always looked at the beautiful return rolled around the edge of the exit hole and dont want to damage it.

Joe