Well Elmers I try again...
I have problems with frequency lockup once a while while powering the
omni VI+ up. (Still )
There has been only few responses.
One case is sure, it helps to have the power supply on all time. (as
suggested)
Then the problem disappers.
I checked the power supply (Drake PS7) Any way are there any of you using
old good PS7 from Drake to power your Omni ???
The PS7 power supply is clean and very stable even with 25A load (not on
TenTec).
Actually I see some oscilaltions while the voltage is powered on
and off but it is about max 3 v overshut and the oscilations varies from
5 to 100nano secounds. Difficult to chatch it with Osciloscope.
One should notice that the Omni's power switch is OFF and only the
xtal owen is on.
Any way I get that lockup from time to time ,if you like it or not.
Does any bodyknow how the frequency is hold ? Is it stored in the
battery backuped RAM ???
Has any body looked at the RESET circuit of the controll processor for OMNI
VI?
There is only a capasitor and resistor. This combination gives us about
10 - 20 mili sek REST pulse for the 80c32 processor. Normally it is enough.
The industry standard specs it to 150 mile Sek.
May be the processor gets alive too fast ???
I decided to change over the RESET circuit with a monolitic reset
circuit from Dallas, it gives a stable 150 mili Sec reset puls after the
voltage has
stabilize itself. The chip look like a small transistor with only 3
connections.
(suits fine in the position of the existing network)
Any sugestions ??? Need your help !!!
Piotr LA9HFA
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Piotr Tomczak Ham call: la9hfa
Nera ASA Tel: +47 6724 3135 Fax: +47 6724 4445
1361 Billingstad E-mail job: pito@satcom.nera.no
Norway E-mail home: la9hfa@qsl.net
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