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THE AM BULLETIN BOARD => Technical Forum => Topic started by: W8ACR on May 14, 2018, 11:18:35 PM



Title: Jennings HV capacitors
Post by: W8ACR on May 14, 2018, 11:18:35 PM
Here is another item that I picked up on my Missouri road trip. These are HV capacitors by Jennings. I have never seen this style of capacitor before. I assume they can be used in similar applications as doorknob caps. Does anyone have experience with this style of capacitor?

Thanks, Ron W8ACR


Title: Re: Jennings HV capacitors
Post by: K1JJ on May 14, 2018, 11:44:40 PM
Hi Ron,

Those are very high quality caps for RF.  Silver plated. They put doorknob caps to shame. I buy them at flea mkts whenever I see them. Most of my rigs use a larger rated version of them for plate coupling or choke bypass.

They probably cost over $150++ each new list from Jennings.   That is a great find.

At 400 pF, a pair in parallel would make good plate coupling and choke bypass caps at 800 pF for a linear amp, or could be used singularly at 400 pF in an AM plate modulated rig.  The limitation is 4KV, though two in series would give you 8KV.

Nice find, OM!

T


Title: Re: Jennings HV capacitors
Post by: PA0NVD on May 15, 2018, 08:39:11 AM
Thats the style f caps we used a lot in 27 MHz RF generators for plastic welding. Not only for DC block and decoupling, also for the low side of PI filters upto 10 kW
Very nice find, congrats


Title: Re: Jennings HV capacitors
Post by: WBear2GCR on May 16, 2018, 03:07:45 PM
Ron,

Those blue ones look like they might contain "materials known in the state of California to cause cancer".

Best get rid of them, asap!
I'll cover the shipping here, where the stuff for proper disposal is available.

(word to the wise, eh?) ;)


Title: Re: Jennings HV capacitors
Post by: Opcom on May 17, 2018, 12:03:55 AM
And as always, I am accepting all intact mercury vapor rectifiers, Mercury contactors, and Mercury-wetted relays. For your convenience and safety!


Title: Re: Jennings HV capacitors
Post by: kb3rdt on May 17, 2018, 02:15:00 PM
There some of them in Kenwood TL-922 HF amplifier!
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