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THE AM BULLETIN BOARD => Technical Forum => Topic started by: Opcom on April 02, 2021, 10:53:06 PM



Title: Rohde And Schwarz Polyskop II - anyone else seen one or have one?
Post by: Opcom on April 02, 2021, 10:53:06 PM
Say hello to the Rohde And Schwarz Polyskop II
I wonder how many of these are left in the world?

It's to the best of my understanding a frequency response analyzer for shecking filters or amplifiers.
This would be an ancestor of the modern network analyzer.
It's very heavy and has lots of tubes on silver plated chassis.
The manual is out there

- From it comes a 0.5 to 1200MHz swept frequency divided into 6 bands.
- The sweep is a bit primitive, as the deflection is driven by a sine wave from the mains frequency, as is the swept oscillator.
- The input is an RF level detector. The circuit under test is connected between the swept frequency and the detector input.
- The vertical scale is calibrated and had a linear or log response chosen by a switch.
- There is also an input to the vertical amplifier in case one wishes to use another signal compared to the sweep.

Some nice pics here:
http://www.radiomuseum-bocket.de/wiki/index.php?title=Rohde_u_Schwarz_Polyskop_II_(2)_SWOB_BN4245/50

a video:
https://www.youtube.com/watch?v=TAfVvDTYHJc

A nice 1-page cut sheet for it is attached
https://www.siwe.be/files/collectie/V300-R&S-Polyskop-II-200pi.pdf

Yah by the way it has a large CRT with electromagnetic deflection, very sweet. I love it, there are apparently a few collectors, and just wonder how many have survived? Are any in use? Mine came on and worked last time it was used maybe 15 years ago, but I am sure it needs caps and whatever else. Seems handy enough for a bit of fun.








Title: Re: Rohde And Schwarz Polyskop II - anyone else seen one or have one?
Post by: w3jn on April 03, 2021, 03:03:15 PM
Yes, it's a network analyzer.  I had one and apart from the funky RF connectors I could never find, it worked well enough.

Ended up giving it away.  I think I still have the transit cover for the face.


Title: Re: Rohde And Schwarz Polyskop II - anyone else seen one or have one?
Post by: Opcom on April 04, 2021, 01:22:51 AM
I've never had the cover for mine unfortunately.

Mine has General Radio GR-874 connectors. There are BNC and N adapters for it, not too costly.


Title: Re: Rohde And Schwarz Polyskop II - anyone else seen one or have one?
Post by: WB6NVH on April 05, 2021, 06:08:29 AM
I have one, I think it is a SWOB IV, presently DOA awaiting its turn on the bench.  A sweep generator and scope in one box, they were used in factory production lines in Europe to sweep align receiver IF's, among other things.  A friend uses one on the Racal RA-17's he overhauls.

There certainly are some optimistic folks on eBay who have these for sale!


Title: Re: Rohde And Schwarz Polyskop II - anyone else seen one or have one?
Post by: Opcom on April 05, 2021, 02:29:54 PM
The -IV is much newer. It's still pretty old though. Hey R&S stuff always goes for some money. I've always wanted one of their receivers but @ $20K it was out of the question.


Title: Re: Rohde And Schwarz Polyskop II - anyone else seen one or have one?
Post by: WB6NVH on April 06, 2021, 01:08:57 PM
I have a R&S 750 Watt AM transmitter circa 1952.  I feel kinda guilty about not having rebuilt it and put it on the air yet.

Around 1992 I rescued it from the collapsed barn of a hoarder ham who had found it at the curb next to the trash cans in a nearby small town, although he had no idea how it got there.  I couldn't see how someone thought the trash men were going to hoist that 400 pound thing as big as a refrigerator into their truck.

Hoarder had removed all the decks and everything was scattered all over the wreckage, tubes mostly smashed, and then the barn collapsed.  I managed to retrieve everything other than some screws and washers.  Ulrich Rohde helped me by finding the manual back at the plant in Germany and copying it for me.  Since then I have learned of several more in this country. Some of the other owners with more time and resources than I, have had theirs on the air, mine still needs restoration.  Crystal control, 4 channels.  Modulator is a set of skirtless 4-125A's while the PA is a TB3/750 (Amperex 5867.)  I was told most were sold to European embassies and federal agencies such as state police, etc..  Funny thing, based on the EK07 receiver that must have gone with it, you would think this transmitter would weigh as much as a Ford F-150. But it doesn't - - maybe 400 pounds.

I also have a R&S LARU, which is a cute little inductance meter that looks sort of like a toaster.

If my Polyskop has a bad CRT I fear I may be up the creek.  But such are the vintage radio gambles.

Geoff
WB6NVH
Monterey CA
AMfone - Dedicated to Amplitude Modulation on the Amateur Radio Bands