Philips PM5705 Pulse Generator

[bd139]

Another purchase... from Scott of TE football fame. Actually arrived in decent condition. Need a pulse generator for something. An AWG will do the job but why buy one bit of gear when several will do the same job and take up 5x the space!

Came with luggage no less

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Surprisingly good nick

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99% of the mass is this huge casting on the back

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Inside

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As yet untested and uncalibrated but there's not a lot to go wrong!

[MED6753]

Why is that crapacitor dented?

[tautech]

Why is that crapacitor dented?

Made like that. Seen a few similar over the years.

[Zenith]

Some large can Philips capacitors from that era had not dents, but stiffening grooves on the cans, as part of the design. I don't recall other makers doing it.

[bd139]

Despite common belief, they are not for stiffening. They are used to contain the large explosion when the interfnal bastards decide to go internal short. The grooves pop outwards so you can identify them like the top of a jar from the supermarket

[tggzzz]

Why is that crapacitor dented?

Tradition.

At least those pots can be unscrewed and some DeOxit Contact dribbled in.

[vk6zgo]

As yet untested and uncalibrated but there's not a lot to go wrong!

Don't fret----Philips will find something!

[bd139]

Well I tested it and it works fine. That was boring!

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(the scope focus is off - need new resistors installing which I haven't ordered yet)

[Zenith]

There's nothing wrong with the odd boring one, especially if you want to use it was a working instrument.

Very often these acquisitions can be too interesting.

[bd139]

I mostly wanted something reasonable quality and broken to futz with. I picked the seller with the vain hope that it was as broken as the Marconi 2022E I got off him and had to build a new frequency standard for. Typical - it worked perfectly!

[Zenith]

The broken ones go for a lower price, and very often a very low price. I sometimes think the seller hasn't tried very hard to fix them, OTOH acquiring and making this old junk work wouldn't be much of a way to make a living, but it is fun.

I've been tempted by the offerings of that particular ebay seller, but haven't yet bitten.

I must write up and report my adventures with an HP 8601A, which was dead when I bought it, but was got working surprisingly easily. I haven't fully investigated it yet. 20 years ago I would have considered it a magical piece of kit, but now, it's a beautiful item from the golden years of HP and a work of art.

[bd139]

Would be interested in reading that. I've passed on a couple of those over the years. They look like a fun thing to play with.

[Zenith]

For a tenner I couldn't resist it. There's probably a tenner's worth of gold in it. It has the 75 Ohm output option. I'd have preferred the 50 Ohm version.

It had been kept somewhere damp and didn't power up. The problem was cleared by giving the mains switch a generous dose of contact cleaner and exercising it. Then with some twiddling, with reference to the manual, and comparing it with modern gear, it seems to do the bizz. A modern DDS AWG would blow the socks off it, apart from the RF noise leakage, and the attenuator, which delivers an output to sub µV levels. So were you to be hard up for an RF sig gen, this would be good from 100 KHz to 110 MHz. It could probably sweep the IF sections of most comms receivers needing visual alignment from 450 KHz to whatever is needed for an RA17, (41 MHz +/- 1 MHz from memory), and it's far less crude than the various woesome wobbulators for TVs peddled in the 60s and 70s. It's a bit big and heavy.

I believe it was part of a VNA system but was also sold separately.

I didn't think there was enough of interest to write up and report, but since you are interested I promise to get round to it. Honest.

[AVGresponding]

If that's at all similar to my 8614A, "It's a bit big and heavy" is a massive understatement!

[Zenith]

They are about the same. The HP8614A weighs 19.5 kg (43 lbs) and has a 19" rack type form. The HP8601A weighs 21 kg (46lbs) and may have been intended to fit into a 19" rack with another unit. You wouldn't want to drop either on your foot.

https://www.radiomuseum.org/r/hp_signal ... per_h.html

https://www.hpmemoryproject.org/wb_page ... ge_10d.htm

When the HP 8601A was released in 1969 it was just under $2,000.

From the HP article linked above

The variety of applications opened to the 8601 by the early seventies, made it a prime investment for the basic RF bench. Among the many different uses that could be listed, a Tracking Generator for the 8553B Spectrum Analyzer, and a Swept Signal Source for the 8407A Network Analyzer, were the most important ones and those which contributed to the large diffusion of the 8601A.

[bd139]

When you have proper kit, you're mostly paying in weight with the RF cans. As Zenith rightly mentions, RF leakage is why you can't get away with some of the AWGs for this. But for casual use they are good enough. You can get reasonable isolation with external attenuator and keeping the AWG far enough away. I was regularly doing stuff down to -90dBm at HF without too much of an issue like that.

I'm slightly loathed to buy any boat anchor kit though because I will inevitably have to move at some point in the next couple of years and it was bad enough last time!!

[AVGresponding]

When you have proper kit, you're mostly paying in weight with the RF cans. As Zenith rightly mentions, RF leakage is why you can't get away with some of the AWGs for this. But for casual use they are good enough. You can get reasonable isolation with external attenuator and keeping the AWG far enough away. I was regularly doing stuff down to -90dBm at HF without too much of an issue like that.

I'm slightly loathed to buy any boat anchor kit though because I will inevitably have to move at some point in the next couple of years and it was bad enough last time!!

You're not going to buy that German frequency meter then?

[bd139]

You're not going to buy that German frequency meter then?

Hell no. I don't want to end in the krankenhaus!

[tggzzz]

I'm slightly loathed to buy any boat anchor kit though because I will inevitably have to move at some point in the next couple of years and it was bad enough last time!!

That won't be a problem if you have one of these
https://www.bidspotter.co.uk/en-gb/auct ... 2b011af366

Given your carless state, note that it will also help you getting home after you have picked it up.

[bd139]

I'm slightly loathed to buy any boat anchor kit though because I will inevitably have to move at some point in the next couple of years and it was bad enough last time!!

That won't be a problem if you have one of these
https://www.bidspotter.co.uk/en-gb/auct ... 2b011af366

Given your carless state, note that it will also help you getting home after you have picked it up.

I suppose I could ride it down the hill from Syon Lane station

Anyway soon to be jobless as well as carless as things went off the trolley (excuse the pun) so that's off the list anyway...

[tggzzz]

Anyway soon to be jobless as well as carless as things went off the trolley (excuse the pun) so that's off the list anyway...

Given my limited experience with a fintech company, I'm not sure whether to be happy for you or to commiserate.

[bd139]

Given my limited experience with a fintech company, I'm not sure whether to be happy for you or to commiserate.

Congratulations are due. I feel a decade younger already.

[Zenith]

So just a not very exciting job and the main problem is that you now have to find another one. I hope you find something more congenial.

[bd139]

So just a not very exciting job and the main problem is that you now have to find another one. I hope you find something more congenial.

Well it was a very exciting job but in the wrong way. Best not be responsible for reliability in a company with a regulatory compliance duty where you can't fix anything due to politics. There are other things afoot I will not post here.

Due to a combination of wise investments, getting away with far more than expected from the divorce and a dead parent, I'm not in a position where I need a job at the moment so I'm going to mull my options for a bit. I did look at buying a house outright, trying to screw the SLC out of money for the rest of this course and staying strategically under the repayment limit by doing everything cash in hand going forward...

[tggzzz]

Well it was a very exciting job but in the wrong way. Best not be responsible for reliability in a company with a regulatory compliance duty where you can't fix anything due to politics.

Wasn't "project/company scapegoat" in the job description a bit of a hint?

... by doing everything cash in hand going forward...

Don't forget HMRC has more powers than the police. Revenue agents on horseback, and all that.

Governments tend to be a bit touchy about people interrupting their money supply. Well, little people anyway.