[TenTec] Omni VI locking up

[Mike Hyder -N4NT-]

Don't know if it'll help you, Jay, but in case you missed the semi-annual
tip, here it is again:
________________________________________________

Your semi-annual Astron tip...

People come and go from this reflector. This is a reminder that many
troubles with Astron power supplies can be cured by grounding the negative
post to the cabinet.  I did it by removing the insulators from the negative
post, scraping some paint from around the hole and putting a lockwasher on
the post when reinstalling.  Below is my correspondence with them about it.

Happy August,
Mike -N4NT-

----- Original Message -----
From: "ASTRON" <sales at astroncorp.com>
To: "Mike Hyder" <N4NT at chartertn.net>
Sent: Tuesday, November 20, 2001 6:06 PM
Subject: Re: RS-35 in an RF environment

MIKE.

1ST CHECK YOUR AC OUTLET GROUND IT MUST HAVE GOOD CONNECTION

2ND. MEASURE FROM THE -13.8V TERMINAL TO CHASSIS, IF NO DIRECT CONNECTION,
RUN A PIECE OF WIRE FROM -13.8V TERMINAL TO CHASSIS.

JANE

----- Original Message -----
From: Mike Hyder <N4NT at chartertn.net
To: <eastron at astroncorp.com
Sent: Tuesday, November 13, 2001 7:56 AM
Subject: RS-35 in an RF environment

Several people have advised me that Astron had a service bulletin for the
Astron RS-35 (and possibly other models) which advised to strap the negative
post of the supply to the cabinet to reduce or eliminate problems caused
when RF energy affects the supply's regulation.  This is in particular a
frequent problem in the amateur radio service.

Could you confirm such bulletin and either email it to me or point me to the
URL that will allow me to view it, please?

Many thanks,
Mike Hyder
__________________________________________________

----- Original Message ----- 
From: "Jay Schwisow" <kt5e at arrl.net>
To: "Ken Brown" <ken.d.brown at verizon.net>
Cc: <tentec at contesting.com>
Sent: Sunday, August 22, 2004 12:20 AM
Subject: Re: [TenTec] Omni VI locking up


Ken,

The power supply I have been using is an Astron 35A.  I may switch supplies
to see if that makes a difference.   I do have an Amplifier but it does not
matter if it is running or not for this to happen.  Amplifier relay is Off
and I am familiar with this relay and of course how it sounds.

Yea, your right about relays and what one person thinks is loud another does
not.  I also agree with you and others that this seems like a power supply
problem/connector problem.  I am going to check the voltage at that Molex
connector.

Thanks!

Jay - KT5E
  ----- Original Message ----- 
  From: Ken Brown
  To: Jay Schwisow
  Sent: Friday, August 20, 2004 12:19 AM
  Subject: Re: [TenTec] Omni VI locking up


  Hi Jay,

  What kind of power supply are you using? I wonder if the voltage
regulation in the power supply has too slow a time constant somewhere. So
that when you let your key up and transmitter PA collector current drops,
the power supply is for just a moment putting out too much voltage. DCC
Input Board has a relay to switch the 12 VDC power to much of the rig. It
also includes over voltage protection. If the supply voltage is too high,
the relay releases to protect the radio.

  Since you did not mention that you are operating split band, or using an
amplifier that requires you to have the "Amplifier Relay" activated, nor did
you say you are using a separate RX antenna, there are not many relays that
should be switching as you key, perhaps only K1 on the Lowpass Filter Board.
That relay should be fairly quiet, I never hear mine. (Some people say that
the Omni VI is not a QSK rig because that relay makes a terrible racket
though, so relays and opinions certainly vary!) If my theory were correct
the meter lamps would go out altogether, unless something is plugged in
wrong inside the radio.

  I suggest that you check to see that the "RELAY [N.O]" (otherwise known as
external amplifier keying relay) is turned off, as long as you are not using
it. Check the user options menu LCO (Linear Control Relay) setting. This
might eliminate some fault in that circuitry as the cause. I think the relay
on the input power board is more likely the one you are hearing.

  Also next time the problem happens, see if you notice whether it occurs
just as you let the key up, as opposed to at key down.

  You may want to try sending a string of dits, or perhaps dahs, while
adjusting the keyer speed. (of course you should be transmitting into a
dummy load for this.) If it is some interaction between the time constants
in the power supply regulation and the keying, you might find a speed that
causes it to happen regularly. Still the fact that the meter lamps are
dimming, rather than turning off, contradicts this theory. If you could
monitor the DC supply voltage with a oscilloscope using DC coupled input you
could also see if this power supply regulation idea is worth persuing.
Perhaps a DMM (digital multimeter) which has a "peak hold" function could be
used to see whether the supply voltage ever goes too high.

  I hope this helps you find the problem. I would be interested to hear
when, and how you resolve it. I have an Omni VI version 2 and have never had
this problem, but if I ever do, your experience solving it would be helpful.

  73 DE N6KB


    Jay Schwisow wrote:

Ken,

I have not tried all the buttons to unlock the rig.  Again, it does not lock
in transmit it just clicks a relay and the display goes blank.

This has happened with the iambic key hooked directly to the rig and most
recentlry through a W5XD IF.  It has never locked in SSB but then again I
have only had 2-3 Qs on SSB.

It has happened on 15, 17, 20,30 and 40 meters.

Meter illumination dims.

Not sure about LEDs....I will pay attention to this.

Thanks,

Jay - KT5E
----- Original Message ----- 
From: "Ken Brown" <ken.d.brown at verizon.net>
To: "Jay Schwisow" <kt5e at arrl.net>; <tentec at contesting.com>
Sent: Thursday, August 19, 2004 1:20 AM
Subject: Re: [TenTec] Omni VI locking up


  What other methods (besides power cycling) unlock it? How about reducing
the PWR control on the rig? Will that unlock it? That information would
be one more clue as to what is happening.

How are you keying it? Microphone PTT button? Straight key to keying
input jack? External keyer to keying input jack? Paddle connected to
internal keyer? Does it do the same thing with any of these keying
methods? Does it matter what band you have it on? Do meter illumination
lamps dim, or just LED display affected? LEDs next to pushbuttons go out?

    intermittent problems with my Omni VI (Opt 3 upgrade) on CW.
Keying it up on CW will sometimes lock the rig (not transmitting) and
      blank
  the display.   There is a pretty good "klunk" when it does this.
      Usually,
  just turning  rig off and back on for it to reset and go on.

This happens into a nicely matched antenna 100 feet from the shack or
straight into a dummy load so it does not appear to be outside RF.

It happens with power settings from 50 watts to 100watts.   I have not
      spent
  alot of time at 5 watts to see if it will happen QRP.  Has anyone seen
      this
  before?

Any suggestions?