| Products > Test Equipment |
| Marconi 2022E RF signal generator repair and refurb |
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| bd139:
I will check it when I bring it up next time :-+ |
| bd139:
After some research and discussion elsewhere this may be a Frankenstein box. The synthesiser board may be from another 2022 series box. Thus another option is now appearing which is to build a replacement crystal oscillator module to restore the original 2022E oscillator and phase lock it to an external OCXO. This is a reasonable solution and allows me to build a GPSDO and distribution gubbins which goes nicely with the top floor balcony of my new apartment :-DD |
| bd139:
Reverse engineered power supply. 5V limits at 2.7 amps. Investigating idle power draw next. Convenient 0.1 ohm sampling resistor in circuit :) Pushing it. 5V option discarded. 12V option discarded. Final option is build internal crystal osc and discipline it externally. |
| AVGresponding:
Is there space for something like an LM323K on a small heatsink, instead of a 7805? |
| bd139:
It's not so much the space but the fact that it has to go somewhere or the junction temperature will be too high resulting in kapoof of the regulator. Also you have to drop 7 volts at 600mA which is about 5 additional watts during heating and then 1.75 additional watts when warm which is all being dumped into a sensitive box full of RF synthesizer :) After doing a KT of all the options, actually building a replacement crystal oscillator for it and phase locking that to an external GPSDO via the ref input seems to be the most sensible solution here with the least number of risks or surprises. I can do this for about £4 too. Plus as mentioned it give me the excuse to futz around and build a GPSDO :-DD I can't find any other differences between the AA1/1 and AA1/3 board doing a full inspection of both other than some additional decoupling and the missing crystal oscillator. |
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