Varmint XL600

[ira parker]

It's got a few problems! Initial inspection no driver tubes (6kv6a) x 2. 9 pin bases 1) grounded, 2) hv board thru choke to pin, 3) input tune , 4) heater volts, 5) heater ground, 6) open, 7) grounded, 8) grounded, 9) open, plate voltage rerouted to 100 ohm 3 turn parasitic up top with two plate clips. My question is what tube subs for the 6kv6a that has the plate cap on top? RF parts list one by national that has a copper strap from pin 9 to the plate cap but they have it labeled as a 6kv6a, which I have never seen with a plate cap! Next item is the parasitic choke shouldn't there be one on each individual tube? If so do I need to change the value of the resistor and number of turns? On to the finals 4 6lf6s (tested good) surprise! but no parasitic what so ever? the only schematic I can find for reference is from a 150 to a 450, the schematic shows 150 ohm 2 turns, no clarification if that is for all 3 on the 450 or for each individual tube? I think it should have individuals for each tube but will it change the values of the choke (resistor and turns)? That's as far as I've gotten, once I get some information on these issues I'll proceed to the hv section caps diodes ect. Thanks Ira

 

[BJ radionut]

2

Thread 'varmint'

Oct 12, 2008

can some one tell me what tubes go in a varmint xl600 or what will inter change thanks..

• 2112

• 

A

Thread 'Varmint Linear Base Amplifier XL-600, tubes + schematic diagram'

Jun 13, 2011

Hello all;
Let me start with an introduction as I feel I have finally found home here at WorldwideDX.

My name is August Cassiato Jr. My handle is Astro, call sign KYY1525 based in Gainesville Florida, U.S.A.

My father's was a Signal Corps. 2nd Lieutenant enlisted in the early 40's and was so efficient working with any electronics & with fixing equipment that he didn't even think about it he just looked at something and said there it is and fixed. His call sigh was WA4TSV. I hope some may recall him although; he went to be with our Lord in 1983.

I tell you truly, his shoes where...

• August Cassiato ASEE
• Replies: 29
• Forum: Amplifiers

 

[BJ radionut]

Post in thread 'Varmint XL-600'

Aug 30, 2018

88_bandit_88,
Check with nomadradio on a keying circuit board I believe he offers.
If I’m not mistaken you load about 4 components on it and wire in about 4 wires to the amp. More modern components used and simpler design.

73’s
David

• Dmans

 

[nomadradio]

The 'skunk stripe' 6KV6 tubes have a G10 adapter ring soldered to the original tube's pins. Serves to 'adjust' the pin connections to match the new type number. The copper foil strip from the plate cap down to pin 9 is what i nicknamed the skunk stripe. It probably would work okay in a color TV, but seemed unstable in amplifiers.

This tube was an effort by Richardson to fill orders that kept coming in for a type they couldn't obtain at any price. We learned to avoid them. Seems to me we figured out the original number that Richardson scraped off. Been too long.

I think it was 6KM6.



73

 

[ira parker]

The 'skunk stripe' 6KV6 tubes have a G10 adapter ring soldered to the original tube's pins. Serves to 'adjust' the pin connections to match the new type number. The copper foil strip from the plate cap down to pin 9 is what i nicknamed the skunk stripe. It probably would work okay in a color TV, but seemed unstable in amplifiers.

This tube was an effort by Richardson to fill orders that kept coming in for a type they couldn't obtain at any price. We learned to avoid them. Seems to me we figured out the original number that Richardson scraped off. Been too long.

I think it was 6KM6.



73

Great info Nomad, I picked up a couple of the 6km6 tubes pins 1-5 are identical to the 6kv6a, pin 9 on the 6km6 says ic I've ohmed it doesn't show any ic to the other pins or the plate cap so that's all good pin 9 on the socket is open, rewired for parasitic and plate caps. Pins 6,7 and 8 are my questions? 6kv6a pin 6 is G3, Pin 7 is g2, Pin 8 is IC. 6km6 Pin 6 is G1, Pin 7 is G2, Pin 8 is G3. The tube socket is wired right for pins 1-5 and 9, Pin 6 is open, Pin7 and 8 are grounded. Pin 1 and 7 are the same on both tubes G2. The schematic I have doesn't show the tube pin outs, the only thing I'm not sure of is pin 6 and 8. 6km6, pin 2 and 6 are G1 with continuity, 6kv6a, pin 2 is G1 with nothing on the other side of G1. Just want to double check before I fire it up with the new power supply and fry something. Hope this makes since. Thanks Ira P.S. the schematic shows G2 and G3 grounded so I think I'm good just dotting the I's and crossing the T's.