An update for the archives or those interested. Weather and my health
finally allowed me to climb.
I ran a 390 foot length of RG6 quad shield (because that's what I had)
from the OR2800 junction box to the RT21. I have only had a few hours to
test but so far it seems to have fixed the problem. No false pulses have
been counted when the rotator isn't turning. I set max speed back to 10
and have performed multiple random rotations ranging from a few degrees
to 360 degrees. Calibration is holding. I verified by peaking on my flea
power 10 GHz beacon 5.6 miles away before and after. There was no change
in the indicated direction.
Note: When I say peaked on the beacon what I actually mean is I found
the ~10 dB down points either side and took half way between them to be
the true heading. The dish has a 3 dB beamwidth of 3 degrees so this is
a reasonable indicator. With the old cable I had been needing to
recalibrate after every few turns of the rotator.
Thanks all for the input and suggestions. It appears a single run of
coax works for me. I should have done this when it first started having
issues.
73,
Paul N1BUG
On 8/1/2024 8:40 AM, Paul N1BUG FN55mf wrote:
I have an Orion OR2800DC and Green Heron RT21 both 3 years old. I have
had pulse counting errors almost from the start. I know the cable is not
in good condition as the resistance between conductors is only a few K
ohms and is not consistent day to day. It used to simply miss counts and
have to be recalibrated frequently. Slowing max rotation speed to 4
helped a lot. Yesterday it started randomly seeing pulses when the
rotator is not moving. This has quickly worsened to the point of being
unusable. With the pulse counting wire removed from the RT21 it does not
see any false pulses, so I think the controller is OK.
Assuming it is just worsening cable problems and not a rotator fault, I
am hoping for a quick temporary fix using what I have on hand for cable.
Can I use a run of coax for the pulse counting conductors? What effect,
if any, would that have on the pulse train with a 350 foot run? I could
use two runs of coax but I guess there would be no advantage since one
of the pulse conductors is ground.
Thanks for any help or suggestions.
73,
Paul N1BUG
_______________________________________________
_______________________________________________
TowerTalk mailing list
TowerTalk@contesting.com
http://lists.contesting.com/mailman/listinfo/towertalk
|