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high stability oscillator option in MSF5000
Posted: Mon Jun 17, 2002 7:51 am
by n5rwc
Some CXB MSF5000 models have a high stability oscillator which plugs into a small module that is tucked up under the RF section and has 2 RCA jacks.
It has 2 pins coming out of the top and comes up through the top of the casing about 1/8 inch which connects into the Uniboard. Can this extra unit be omitted without any hassles?
Thanks for the help.
Posted: Mon Jun 17, 2002 4:32 pm
by xmo
"Can this extra unit be omitted without any hassles? "
Other than that the radio won't work?
Assuming what you are refering to is the A2502 external reference connector assembly, it feeds the 14.4 MHz from the HSO tray into the uniboard.
A high stability uniboard has no 14.4 reference of its own, so without the HSO tray connected through the A2502 the station can't lock its synthesizers.
external reference oscillator
Posted: Mon Jun 17, 2002 7:17 pm
by n5rwc
Ahhh...thanks for the info! I am flying blind but am very interested in this. I called Mot to order the correct book for it but until later this week I have been learning on line as much as I can so thank you. Is its hook up simple? I see the power connect cable and a small cable with a rca type male connector on it. I am not sure if I have everything I need. Would you have any more information on this you could email me or fax to me?
Tim
Posted: Mon Jun 17, 2002 8:17 pm
by xmo
Your radio is dis-assembled?
The RCA from the HSO tray plugs into the A2502 and the power connects to J500 on the interconnect board.
Some HSO stations have an internal reference and some have a BNC on the cabinet side panel that hooks up to a site frequency reference.
(in which case the left hand side of your reference synthesizer tray will be vacant - no oscillator - and you will have to supply the station with a reference - usually this is 5 MHz)
Posted: Mon Jun 17, 2002 9:03 pm
by n5rwc
No not dis-assembled. It's came as another section (drawer with mounting hardware) under the RF section intact. It was removed from service - control shelf, rf section (where the uniboard/voc's are located) and under that sits the HSO.
J500 on the interconnect board is void of any connection at the moment as well as J501, J901, J603, J502A and J596A. Many of these cables were just cut I believe and or thrown away in i'ts removal. I have a source that I called today that says they have several that they can give me for little money so I think I will take them up on the entire lot just to be safe.
The HSO has the yellow lead that is fused, white lead with an RCA and one or two others of different colors - I am not at the unit at the moment but wish I were to give you the exact makeup of the connections that are indeed still on the HSO. But as best as I recall that's really close.
There is a small device located on the underside of the uniboard just outside of one of the VCO's labeled Digital Modulator on one connection and Reference Frequency on the other - both are RCA type.
Posted: Thu Jun 20, 2002 4:53 pm
by n5rwc
Just looking over the book I got today from Mot. I think I got it. This is a "high stability oscillator option" C574 and not an "external reference option" C573 which requires an external 5 HMz reference signal.