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Marconi 2022E RF signal generator repair and refurb

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AVGresponding:
Looks simple enough I guess. Is the pcb layout available?

bd139:
It's in the 2022E SM but I will just dead bug one on some FR4. I may do a proper PCB if I can be bothered with it down the line but I want to prove the idea works first and check the entire unit over properly before I throw too much money and time into it.

I need to order an N to BNC adapter anyway and Rapid seems to actually have all the bits I need for once. Will recycle some of the parts out of that HP create you pointed me at as well  :-+

Ordered - Rapid:

10x 120pf NP0 ceramics
10x 22pF ceramics
2x ACT 10 MHz crystals (30pf loading to match the original)
1x RF solutions N to BNC adapter
100x 100nF X7R ceramics (for stock)
100x 1N4148 (for stock)

Ordered - Langrex:

3x BB809 varactors

Bang goes another 20 quid  :-DD

AVGresponding:
Glad you have some 150MHz transistors in stock, and didn't throw them out with the recycling!   :popcorn:

bd139:
Don't even go there  :-DD

Any generic NPN will do this job so usual suspects 2n3904 / 2222 / BC547 etc are fine. I will reuse the Motorola 2N2222A's extracted from the 3776A for this only because I quite like metal can transistors :)

Fraser:
I own a three versions of the venerable Marconi 2022 RF sig Gen.

These Sig Gens are still sought after due to their compact size and decent performance. The most common fault on them
is failure of one of the Philips OM series gain block hybrid amplifiers. Those hybrid amplifiers were common and relatively inexpensive in the 1980's. They were cheap enough to be used in TV aerial booster amplifiers as a gain building block component. Sadly their relative rarity in the modern world has made them somewhat more expensive. I have a 2022 that has suffered failure of many front panel button switches and that is a project that I will get around to doing when time permits.

For information, the 2022E model was specified by the UK MOD who needed a tactical field use signal generator which did not have a long settling time before producing a stable output frequency. The OCXO was ditched and a TCXO employed to meet that fast set-up and use requirement. For the MOD application precise frequency accuracy was less important than the speed with which the unit became frequency stable. I personally like my 2022E as it is portable, fast to use and its accuracy is more than enough for most tasks that I have for it. If not, I connect a small Quartzlock 2A off-air frequency standard to it that uses the BBC Radio 4 198KHz carrier as its reference. 

From memory I own two 2022's, one 2022C and one 2022E. I was going to sell one or two but could not bring myself to do it as I have used these a lot in my career and I have a soft spot for them. I sold my bulky Marconi 2019 RF signal Generator instead.
I believe that I may also have the service manual for the 2022E model, but sadly I am many thousands of miles away from home for a while so cannot check.

Good luck with the restoration  :-+

Fraser

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