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Re: Daytime Impedance high?

Posted: Thu Jun 22, 2017 7:36 am
by RGORJANCE
Deep:

Thanks for the update re coil parts from Gates Air.

Good thing I got some spares on hand for those coils, and two spare coils. Now you got me wondering about the motorized contactor parts. Only got a couple fingers left for them. :(

Fossil

Re: Daytime Impedance high?

Posted: Thu Jun 22, 2017 9:05 am
by lbwireless
LBA Technology has been supplying RF components and systems for many years Their products are at https://www.lbagroup.com/products/technology. Your contact on the coil would be Jerry.Brown@lbagroup.com.

Re: Daytime Impedance high?

Posted: Thu Jun 22, 2017 10:05 am
by Deep Thought
RGORJANCE wrote:
Thu Jun 22, 2017 7:36 am
Deep:

Thanks for the update re coil parts from Gates Air.

Good thing I got some spares on hand for those coils, and two spare coils. Now you got me wondering about the motorized contactor parts. Only got a couple fingers left for them. :(

Fossil
I had the same experience. The "incident" in Palm Springs a couple years back was remedied with a new exact-same coil from GatesAir (both the engineer and I were amazed they had one) but the second flameout in Minnesota earlier this year resulted in a "no we don't have any more of those" and the referral to KTL.

As for the spam above this post, just don't. :roll:

Re: Daytime Impedance high?

Posted: Fri Jun 23, 2017 10:07 am
by Steve Brown
Fossil and anyone else who might be interested. Contract engineer Doug Thompson knows where there are at least four of the Harris sliding motorized contactors that were replaced with Kintronics contactors some years ago. The Harris contactors didn't seem to want to slide well in cold weather here in MN. Contact Doug at (651) 247-8119 if you're interested.

Radio Ranger, Mpls

Re: Daytime Impedance high?

Posted: Fri Jun 23, 2017 10:42 am
by awsherrill
When Harris had their big inventory sell-off a few years ago (prior to the broadcast division getting spun off and becoming Gates-Air), did they have any AM parts and pieces that wound up being purchased by someone? I recall that SCMS wound up with a fair amount of Harris stuff.

Re: Daytime Impedance high?

Posted: Fri Jun 23, 2017 12:23 pm
by lbwireless
@Deepthought - Spam, indeed. My post was meant to be helpful and you have no basis for impugning it.

Re: Daytime Impedance high?

Posted: Fri Jun 23, 2017 3:57 pm
by NECRAT
lbwireless wrote:
Fri Jun 23, 2017 12:23 pm
@Deepthought - Spam, indeed. My post was meant to be helpful and you have no basis for impugning it.
Check your PMs.

Re: Daytime Impedance high?

Posted: Wed Jun 28, 2017 3:01 pm
by grich
Hopefully the original problem doesn't become moot as a tornadic thunderstorm threatens the KMA tower site here in the next few minutes...

Re: Daytime Impedance high?

Posted: Wed Jun 28, 2017 3:32 pm
by Shane
Sounds like they made it through. Praise God, the funnel lifted as it crossed Shen just a few blocks south of downtown. The same storm is well east now and the funnel has been up and down and up again.

Pretty intense hail not too far from the KMA site but never lost carrier. The NWS EAS relay was interrupted a few times.

Great coverage, KMA folks!

Re: Daytime Impedance high?

Posted: Wed Jun 28, 2017 9:23 pm
by mbrockm
We will see what daylight shows tomorrow at KMA sites

Re: Daytime Impedance high?

Posted: Mon Jul 10, 2017 5:29 pm
by mbrockm
I got my replacement coil from Kintronics today. The old coil was a 6" outside diameter coil with 23 turns. The replacement from Kintronics is only a 5" outside diameter coil with 22 turns. The windings on both are 1" wide flat copper. Circuit wise the coil is across the common point and ground. The wiper arm adjusts the power to the south tower in the DA. Is this going to work? The difference in coil size has me wondering if this will work. Attached our phasor diagram. Coil is L6 in the south tower circuit.

Re: Daytime Impedance high?

Posted: Mon Jul 10, 2017 10:23 pm
by Deep Thought
That is a very non-critical part of the circuit, forming a power divider based on roller position on the coil and the ratio between the "top" and "bottom" parts. You may notice a small difference in phase (<5°) due to the slightly different coil value and it'll probably shift the common point tuning a bit, but neither of those are issues with most phasors.