I wouldn't totally discount the possibility of RF sneaking back in where it
wasn't supposed to - the cable to the footswitch could be functioning as
a "Murphy"* antenna. Might a snap-on ferrite choke or two help?
* "Murphy" as in "Murphy's Law" or "If something can go wrong, it will,
especially during the contest" (AKA Murphy's Law for Contesters.)
73, Al
On Wed March 6 2013 12:38:38 am PA5MW, Mark wrote:
> Some more info from last weekend:
>
> During the ARRL X SSB, similar failures were noted during the first day.
> It was found that when our BOG antenna was connected via a RIP-1 K9AY
> front end protector, things went wrong.
>
> On sunday morning, we opened up the ORION and performed the actions with
> all cables as you described below.
> One hour later we were back on the air and things went OK till the evening.
> At that point the issues showed up again. Carefull investigation by the
> team showed that:
>
> Connected BOG antenna via K9AY front end protector in the PTT circuitry
> + using the PTT footswitch for TX = intermittent problem
>
> Same but using F1 CQ button in N1MM for TX= never any problem
>
> That exact combination proved why similar problems during our national
> PACC contest early feb(where the footswitch was used), and the 160m SSB
> turned up.
> From here on we need to investigate further.
> But we are getting closer :)
>
> 73 Mark, PA5MW
>
> On 27-2-2013 23:36, Carl Moreschi wrote:
> > My best guess is the cable connections behind the Orion front panel
> > need cleaning. There are a lot of microprocessor cable connections
> > there and you can get almost any symptom if one of the connections
> > starts to fail.
> >
> > Remove the front panel which is not difficult. Then unplug the cable
> > connections, spray them with a good cleaner, and then plug them back
> > in and out about 10 times to clean them.
> >
> > That fixed my Orion and my son's Orion which had strange symptoms.
> >
> > Carl Moreschi N4PY
> > 121 Little Bell Dr.
> > Hays, NC 28635
> > www.n4py.com
> >
> > On 2/27/2013 4:49 PM, PA5MW, Mark wrote:
> >> The ORION at our clubstation PI4TUE recently showed some issues:
> >>
> >> Weekend before ARRL during 24hr PACC contest:
> >> - abt 30 times RX quiet
> >> - sometimes TX-freq slowly drifted away during transmission by couple of
> >> ten's (different bands and modes)
> >> - at some point RX seemed deaf for abt 5min and we noticed we got
> >> spotted on 6995-ish instead of being in the 7030-7040 range
> >> We had to shutdown each time to solve the issue
> >>
> >> ARRL DX CW contest:
> >> First hour in the contest offered same RX anomolies
> >> Changed PA timing settings in N1MM and raised TX delay on the ORION
> >> to 65%
> >> No single issue noted during the remaining 46hrs
> >>
> >> Last weekend:
> >> Main operator noted during transmission (160m SSB) the TX drift is back
> >> again
> >>
> >>
> >> Remarks:
> >> None of the equipment (ORION, PSU, PA, PC's, Winkey, SteppIR) in the
> >> shack is linked on their ground connections.
> >> Equipment is effectively grounded via their mains connection to 1 mains
> >> supply group, the several interlink coaxes and the antenna coax
> >> connections to the building grounding system on the 220ft high roof (
> >> huge matrix of professional lightning protection).
> >>
> >> Several other coax interlinks have been used, but the current Aircell 7
> >> (especially the PL259 for that) proved intermittent at some gnd
> >> connections in the past. Cables have been cut and re-installed.
> >>
> >> ORION is an early 2002 (?) model with slightly darker s-meter compared
> >> to my own 2004 model at home.
> >> Has had the PSU board upgrade with the exact required specced low ESR
> >> caps in 2008 from Digikey
> >> Defective headphone opamp on front pcb was exchanged in 2011, not a
> >> simple operational task
> >> DC supply molex connection+25 ampfuse contacts are cleaned and ok
> >> DC suppy is normally set at 15VDC
> >> DC supply cable has a #31 ferrite with abt 11 turns for CM rejection
> >> Amp is an Acom 1000 set for 400W ouput
> >>
> >>
> >> Anyone any clue about the strange behavior mentioned above?
> >>
> >> 73 Mark, PA5MW
> >>
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