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THE AM BULLETIN BOARD => Technical Forum => Topic started by: Chris P. on August 12, 2019, 02:11:29 PM



Title: Homebrew Oscillator/Exciter
Post by: Chris P. on August 12, 2019, 02:11:29 PM
I recently picked up this interesting exciter deck at a fest. Someone did a great job building it. I think the oscillator tube may have been an 802? and the buffer an 807. It looks like the crystal oven plugged into the 5 pin socket behind the window.

Kind of a strange setup. Also, the tank for the buffer resonates on 160 with the variable cap only about 25% meshed. That along with having a crystal oven makes me wonder if it was used for something other than amateur use. Maybe AM broadcast?


Title: Re: Homebrew Oscillator/Exciter
Post by: Chris P. on August 12, 2019, 02:14:36 PM
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Title: Re: Homebrew Oscillator/Exciter
Post by: K4RT on August 12, 2019, 05:08:21 PM
Hi Chris,

I like your call sign.

That is an interesting set. Hope to hear it on 160m soon. I’m wondering what is the resonant frequency.

73,
Brad K4RT


Title: Re: Homebrew Oscillator/Exciter
Post by: W7TFO on August 12, 2019, 08:16:46 PM
It looks like a Conelrad oscillator for 1240 kc.

https://en.wikipedia.org/wiki/CONELRAD

The first BC station I worked for had one to shift from 1400 to 1240.  A real pain in the ass to implement.

73DG


Title: Re: Homebrew Oscillator/Exciter
Post by: Chris P. on August 13, 2019, 09:37:27 PM
Hi Chris,

I like your call sign.

That is an interesting set. Hope to hear it on 160m soon. I’m wondering what is the resonant frequency.

73,
Brad K4RT

Hi Brad,

Didn't see you at Berryville. I'd like to have something new for 160 this winter. Maybe this will be part of it?


Title: Re: Homebrew Oscillator/Exciter
Post by: Chris P. on August 13, 2019, 09:41:39 PM
It looks like a Conelrad oscillator for 1240 kc.

https://en.wikipedia.org/wiki/CONELRAD

The first BC station I worked for had one to shift from 1400 to 1240.  A real pain in the ass to implement.

73DG

It very well could be that. Makes sense.

It'll make a neat xtal oscillator or even vfo with some work for 160


Title: Re: Homebrew Oscillator/Exciter
Post by: K4RT on August 15, 2019, 12:06:19 PM
Hi Chris,

I couldn’t make it to Berryville this year.

Keep us posted on your 160m project. Thanks for posting the pics.

I’m building a new shack so I hope to have the station set up again and be back on AM by September including 160m.


Title: Re: Homebrew Oscillator/Exciter
Post by: Opcom on August 15, 2019, 10:12:37 PM
Beautifully made. Very dignified.


Title: Re: Homebrew Oscillator/Exciter
Post by: W2PFY on September 09, 2019, 02:31:25 PM
Quote
I think the oscillator tube may have been an 802?

Did you figure out if it is indeed 802 tube? If so, I have a one NOS for free if you are going to use it. One catch, its at my camp and I would not be able to mail it for a few weeks from today. The camp is 125 miles from here and I plan to go up there later this month. PM me if interested.

My best,

Terry
W2PFY
AMfone - Dedicated to Amplitude Modulation on the Amateur Radio Bands