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Author Topic: VRL Globe King  (Read 62419 times)
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VE3AJM
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« Reply #75 on: January 28, 2013, 08:31:44 AM »

The GK500 should have 1500 volts on the plate of the 811s.  Did  you really measure 2000 volts?  Interesting.

C



I measured the B+ voltage on the 811a modulators in my GK500A at just under 1100 VDC, and the final at about 1850 VDC which is in line with what the schematic shows in the manual, give or take a bit.

Maybe yours has a different plate transformer in there or something?

I don't get bumping up the B+ voltages on the modulator and final in the VRL unit, but continue to use a VERY undersized plate tuning capacitor for the final. Thats just asking for trouble with arc overs etc. across the plates of that cap. And unlike the GK500, there is space on the chassis to accomodate a larger air variable plate tuning cap.

Al VE3AJM

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Pete, WA2CWA
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« Reply #76 on: January 28, 2013, 10:42:49 AM »

If I was to tackle this project, the first thing I would do is to retrace every wire and part and create a schematic of what I had. I would not rely on some 60 year old design criteria when it can't be verified the builder even followed it.
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ke7trp
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« Reply #77 on: January 28, 2013, 12:23:38 PM »

Thats good advice to think of this as its own transmitter wQ9e.

VE3AJM-My modulator plate supply was changed. The original was bad.  Sorry. i forgot about that. Mine has 1550 volts on the 811s. I had to get my notes out. Mine also has the 500 volt LV supply taken off the main supply as the replacement modulator power trans did not have a 500 volt tap on it.  My idle is about 50MA.  Its been like that for 5 years now.  Sorry for any confusion on the voltages.

A schematic would be nice to have for this transmitter. It think once the bugs are worked out its going to probably produce a solid 400 watts and sound great.




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KD8PIQ
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« Reply #78 on: January 30, 2013, 10:38:36 PM »

Can someone please tell me the name of this female receptacle; and the name of the male plug that mates to it.

It is for the interconnect cable from the Power supply deck, to the RF deck.

I hope to order male ends from http://www.mouser.com to fabricate a new cord.

Thank you for your time! 

-KD8PIQ

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Do just once what others say you can't do, and you will never pay attention to their limitations again. James R. Cook.
ke7trp
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« Reply #79 on: January 30, 2013, 10:58:30 PM »

I believe that is the 5 pin Amphenol socket.  A google search for 5 pin amphenol plug will return vendors on auction sites and websites

http://store.triodestore.com/86cp5.html

C
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KD8PIQ
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« Reply #80 on: January 30, 2013, 11:20:07 PM »

I believe that is the 5 pin Amphenol socket.  A google search for 5 pin amphenol plug will return vendors on auction sites and websites

http://store.triodestore.com/86cp5.html

C

Not quite, but close.  These I have are 6 pin.  I'm searching around on the web.
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ke7trp
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« Reply #81 on: January 30, 2013, 11:26:57 PM »

Clearly thats a 5 pin.. Unless you are saying the Center is a pin also.. I think I can see there is a contact there.  I have never seen that style of that is what it is.. Maybe someone else can comment.

C
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Pete, WA2CWA
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« Reply #82 on: January 31, 2013, 02:50:38 AM »

Plugs originally made by Amphenol as the 91MPM3L (3 pin), 91MPM4L (4 pin), 91MPM5L (5 pin), and 91MPM6L (6 pin). No longer manufactured.

I wrote this in 2006:
Lafayette, and probably others, used the five pin version on their early tube CB's. Lots of time you can find the matching mike with the five pin plug on it at a hamfest. If you line up the five pin plug with your 4 pin socket, you can see quickly which pin to cut off. Lafayette HE-15, HE-20A/B/C, HB-111, 200, 222, 333, HE-35(I think), HE-45 series all used the 5 pin version. The 3, 4, 5, and, there was a 6 pin version, were also used on some 50's and 60's audio equipment.

The Thunderbolt requires the 4 pin version.

Personally, I would find a male and female plug/socket that are currently made and available and that can roughly fit the hole. It would be scary to run any kind of high voltage through that old plug/socket combination.
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KD8PIQ
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« Reply #83 on: January 31, 2013, 10:28:34 AM »



Personally, I would find a male and female plug/socket that are currently made and available and that can roughly fit the hole. It would be scary to run any kind of high voltage through that old plug/socket combination.

I think that is the best way for me to go.  Thank you for the great info though.
73's
-Scott, de kd8piq
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Do just once what others say you can't do, and you will never pay attention to their limitations again. James R. Cook.
VE3AJM
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« Reply #84 on: January 31, 2013, 07:04:13 PM »

I saw a Millen HV type connector mounted on the centre back of that chassis as well. So apparently B+ and modulated B+ would be routed through that connection. I think I saw the cable in a pic on page 1 of this thread.

Al VE3AJM
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ke7trp
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« Reply #85 on: January 31, 2013, 09:04:29 PM »

And if you need those HV connectors you can get them at a good price from Ted at Henry.  Just email him.  He will include the HV/old style spark plug wire.

C
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KD8PIQ
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« Reply #86 on: February 01, 2013, 12:33:47 PM »

I have the cord for the HV.  Thank you!

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Do just once what others say you can't do, and you will never pay attention to their limitations again. James R. Cook.
KD8PIQ
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« Reply #87 on: July 06, 2013, 10:42:20 PM »

Made my own interconnect for the decks today with some spar parts.
Fist time I have had the final lit up.  The final is used, but I will still let it burn in for a few before further testing.

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Do just once what others say you can't do, and you will never pay attention to their limitations again. James R. Cook.
KD8PIQ
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« Reply #88 on: July 07, 2013, 09:22:36 PM »

I let the tubes burn in all night, and most of the morning.  I now have both decks on the bench, preforming alignment procedure on the WRL 755A VFO.

I had to drill a few extra holes in the power/mod deck under the 755A to gain access to L3, and C6.  Holes already exist for L4, and C3.

I use a 1k Resistor in series with my receiver ant. from the VFO output; for Zero Beat tuning.
Obtaining Zero Beat on 1.8mc, and 7mc was a breeze.
2.0mc, and 7.4mc did not seem to show.  I tuned C6, and C3 for best RX of short wave I heard. 

I stopped at this point for this post.  I hope a wise ham out there will tell me whats up.   

Thank you!
de kd8piq 
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Do just once what others say you can't do, and you will never pay attention to their limitations again. James R. Cook.
flintstone mop
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« Reply #89 on: July 09, 2013, 06:46:28 AM »

From what I am seeing in the construction of this transmitter, is that the layout and wiring and placement of components looks very nice. Wherever the weak spots are in electronic design, find them and make it work. It's just an Amplitude modulated transmitter using tubes. No computers or microprocessors involved.
You probably have one of the few of those TX's that works. Or you get the bugs out and it happily makes AM RF for on the HAM bands.
I think you did ok in this deal.
Thanks for the nice detailed pics. Good luck with 4 kids...I am 67 dealing with one 7 yr old...toooo much energy!!!
Fred
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Fred KC4MOP
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