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Author Topic: Globe King 275 /275A  (Read 5850 times)
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N8ZRD
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« on: November 07, 2017, 06:10:46 PM »

Hello All,

I have recently acquired a couple of Globe Kings..one is a 400 C and the other I believe is a 275/275A.  Both are semi functional and will be on the air soon.  My question is .."Does anyone here have a 275 /275A that could share some info with me ? "   There is very little that I can find on the internet??  I do have a manual and have attached a couple of pictures.

Tnx es 73
Kent
N8ZRD


* GlobeKing275A.jpg (4239.44 KB, 4032x3024 - viewed 570 times.)

* 275front.jpg (4574.7 KB, 4032x3024 - viewed 577 times.)
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K4RT
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« Reply #1 on: November 08, 2017, 10:45:42 PM »

Kent,

I seem to recall ER publishing an article about the GK 275, although I'm not certain. If you don't already have it I will look for it this weekend and if I find it send you a copy.

Good luck with your GKs.  I have a 500B.

73,
Brad
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KD6VXI
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Making AM GREAT Again!


« Reply #2 on: November 08, 2017, 10:51:29 PM »

Love the visible blowtorch and butt wipe

Must have been getting ready to plug it in! Lol

--Shane
KD6VXI
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KC4VWU
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« Reply #3 on: November 09, 2017, 02:26:22 AM »

The RF deck looks similar to the one in my 400. Probably the only difference between it and a 400 (basically) is the mod deck. Yours, looking  at the pics, would run a quad of 6L6's in p-p/parallel, and the 400 used a pair of 5514's (mine uses Taylor TZ-40's as labeled on the chassis). Should be quite close to the 400 except for that minor difference.
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N8ZRD
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« Reply #4 on: November 10, 2017, 08:14:42 AM »

Thanks for the replies!!  Both GK's are working somewhat now...problem I am having is that neither will load to more that 75-100 ma and only about 30 watts out...Modulators are also working with good audio from a d-104...only tried modulators briefly as the manual says not to try to modulate the final PA unless fully loaded and making full power( 280-300ma for V-70ds)

I have read that the issue may be with the Final Grid coil and a cap thats in series to ground on the link to the grids of the V-70d's??  Will be doing further tests this weekend to confirm 807 is good and grid drive to the final stage. ( also have multiple v-70d spares and swapped a few in with same results)

Any thots on this?

Tnx agn es 73
Kent
N8ZRD

Pics is of my 400C


* GlobeKing400C.jpg (3614.85 KB, 4032x3024 - viewed 294 times.)
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KC4VWU
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« Reply #5 on: November 11, 2017, 03:23:24 AM »

Have you tried an xtal? What is the grid drive reading to the finals? All the coilsets the correct freq? How many turns on the output swinging link? You'll probably have to shunt in some extra C in the output when it's all said and done.
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N8ZRD
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« Reply #6 on: November 11, 2017, 02:29:08 PM »

Tnx Phil and all.

Yes...have tried crystals( no grid drive at all) and a Globe VFO...can dip the oscillator and buffer but no grid drive/current to the final....however...when switching the vfo into the Spot position( higher output from VFO)  setting I do get about 50 ma final grid current.  ( also..coils are correct as per the manual)
Adjusted the link in the grid coil to 32ma grid drive as per the manual and can get the final to load up to about 175 ma...meter then shows about 85-90 watts out .

Here's the strange part..the oscillator tube is a 6AG7 instead of a 7C5...obviously the socket was changed as the 7c5 has a Loctal base!

Also..the buffer/driver tube is a S2001A assumably from a Yaesu/Kenwood hybrid!  Pulling the RF/Exciter deck next to verify 6ag7 conversion was done correctly.  Also tried a 6146 in the buffer/driver with same results...will also check that circuit for mods.

Swinging link in the PA has 8 turns...4 inside of 4.

Briefly plugged in a mic and the modulated waveform looks good on the scope and sounds ok too!

Tnx es 73
Kent
N8ZRD

Thots??
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KC4VWU
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« Reply #7 on: November 13, 2017, 02:54:05 AM »

What freq. are you doing the testing at?
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N8ZRD
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« Reply #8 on: November 13, 2017, 06:55:33 AM »

40 meters....7290 and 7295 crystals
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N8ZRD
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« Reply #9 on: December 13, 2017, 05:59:21 PM »

Hello All,

Thought I would post an update on the Globe Kings...the 400C is making RF with a crystal now albeit with sorta low grid drive..abt 30ma.  Power out is around 200 watts with plate current at about 200 ma give or take.   I have several sets of V-70D's and all are making the same power and current readings so I'm guessing they are all good! ( or maybe all soft!!! hi)

Had to make up an 80MEL coil for the oscillator as I only had one. Been testing on 3.885 with a crystal.  Final link is fully meshed for output and Modulator seems to be doing 95-100 percent and sounds pretty good!!

I have taken a couple of high voltage readings under load and both the Simpson and my High voltage probe show just over 1200 volts. Thinking that may be a bit low but I am just getting started with the check-outs. 

Can anyone tell what their 400's are doing for output with the V-70d's??

Merry Christmas to All!!
Best 73 de Kent
N8ZRD
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