need help with nitro 300 tube base amp

[fnkycoldmedina]

first i thought i blew the tubes ...5-6lq6 in this ..until i took a closer look.when i turn the load control it makes the connection at the tune control start to flame up.it will flash sizzle and spit flame .......thought maybe bad solder joint so i resoldered it all ...still the same ....then i was told the caps in the strip that hold all the cap wires...pulled them and they were ok...not shorted.didnt know how to check the choke but when put on the ohms meter it would make the meter buzz...like dead short i guess...but this is a choke so i dont know...the choke is unmarked.the caps were .001m 3kv..2 of them .the tubes are all ok...i can even get a little power out but if i try to dial up too much load the tune control will flame up at the connector .....help...........any ideas?this is a transel nitro 300 with 5 6lq6's.....this beast was swinging 800 befor all this happened..just seen a flash one day....could the load n tune controls need replacing??

 

[nomadradio]

Sure sounds like the Load control has been damaged.

The first time an arc jumps across the gap in the Load control, the surface of the plates gets damaged. A smooth metal surface has a higher breakdown-voltage rating than the torn-up, rough surface that it has after the arcs begin. The high temperature of the arc will melt and pit the plates' surfaces, making it break down at a MUCH lower power level than before.

Replacing the Load control won't fix the problem that started the arcs in the first place. A close look at the surfaces of the contact points in the relay may reveal the source of the original problem. Arcs across the contact points on the relay are a common root for this trouble. Once the Load control is damaged, things just go downhill.

If the Tune control gets torn up enough, you could have to replace both, to make it behave again.

73

 

[fnkycoldmedina]

thanks for the input.i did look at the relay too as i had suspected maybe the relay was bad .its hard to get to in this amp kinda.i have found a replacement tune control .i will try to get to the relay and clean the contacts .the relay does still work so i will try to clean it .if after doing all this the amp still wont work properly i will offer it up for sale "as is"and maybe sell all the tubes off seperatly.the tubes all test good on my tester......thanks again for your input and if you think of anything else please share ...thanks