[evlatests] Ant11 4 meter problems

[Dan Mertely]

At Chuck's request, I just went out and traced the
ant11 4m RF path from the external X-dipole feedlines,
through the feedcone bulkhead, to the 74 MHz box, out
the 74 MHz box to the LOIF rack input bulkhead, and from
the LOIF rack input bulkhead to the T301 4/P converter
module.  *All RF cabling appears correct* as shown in
the attached Gerry Petencin drawing from 1998(with my EVLA mods).

The only (minor) thing I saw wrong was that the inside,
feedcone bulkhead type N connector was about 1.5 turns
loose.  I tightened it.   This check and adjustment was
done between 11:30 and 12:15 today.

-Mert


Ken Sowinski wrote:
> On Thu, 9 Aug 2007, Ken Sowinski wrote:
> 
>> The Flukes are not set right, so all the VLA antennas are not
>> coherent with eVLA antennas.  There might be even more wrong
>> with VLA antennas.
> 
> This occured when using the default frequency for 4 meters
> because the wrong value was entered in the data base.
> In addition the alternate input switches were not being
> set for 4 meters; the fix for this has been commited.
> 
>> The working EVLA antennas seem to be polarized at random.
>> 11, 17 and 26 are in one state;
>> 18, 19, 21, 23 are in the other.
>> Without a clearer majority I am not willing to say which group
>> is correct.
> 
> There is now some evidence that the group including 11, 17 and 26
> are wrong.
> 
> About 15 minutes of data were taken for Rick with everything
> owrking so that he can provide a summary of what works and
> what does not.
> 
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