Royer Mod Problem

[nacho459]

I just finished the first of two 2001 mods and I have a problem, The output is LOW, and I don't mean dynamic low but have to crank the gain on full to get a decent level low. It's also really thin sounding, like if it was missing a pin or there is an impedance problem. Any Ideas?

 

[Marik]

Triple check if all the wiring is right, all parts values are right, grounding is right, and you connected trafo right way. If all that is OK, check voltages on the tube pins and post it.

 

[nacho459]

My RCA Recieving Tube book didn't even have the 5840 so I'm not even sure on the tube pins, at first I counted them like a 12AX7 clockwise looking from the bottom. But didn't get much of anything so I swapped it out and whola I got something. I checked the layout and schematic and everything for about an hour and couldn't find anything wrong. I'll find the voltages at work tomorrow.

 

[Marik]

How did you swapped it???? :shock:

Here is 5840 data. It shows bottom view:

http://www.pmillett.addr.com/tubedata/HB-3/Receiving-Type%20Industrial%20Tubes/5840.PDF

 

[zebra50]

[quote author="nacho459"]My RCA Recieving Tube book didn't even have the 5840 so I'm not even sure on the tube pins, at first I counted them like a 12AX7 clockwise looking from the bottom. But didn't get much of anything so I swapped it out and whola I got something. I checked the layout and schematic and everything for about an hour and couldn't find anything wrong. I'll find the voltages at work tomorrow.[/quote]


Clockwise looking at the bottom sounds right. The royer articles show which pins go where.

You could have problems if you have accidentally hit the heater with 100V - it may have fried!

 

[Gus]

Is the tube new or a pull you got from Apex?

Check the transformer for continuity I know someone that had a problem like this with a microphone the transformer was bad, primary was open.

 

[nacho459]

[quote author="zebra50"]You could have problems if you have accidentally hit the heater with 100V - it may have fried![/quote]

The Heater is pin 3 & 6 so even backwards it is still 6 & 3. I hooked it up like that first and got absolutely nothing. so now it's back wards and it works better. I think I'm gonna try swaping out the jensen.

And the tube is new, I ordered it from Antique Electronics.

 

[Marik]

[quote author="nacho459"][quote author="zebra50"]You could have problems if you have accidentally hit the heater with 100V - it may have fried![/quote]

The Heater is pin 3 & 6 so even backwards it is still 6 & 3. I hooked it up like that first and got absolutely nothing. so now it's back wards and it works better. I think I'm gonna try swaping out the jensen.
[/quote]


?????
It seems that you do things randomly--you'll never get anywhere with this approach. First, check your trafo for continuity, as Gus's suggeted (swap it only if it is busted), then connect the tube the RIGHT WAY, and check and write down voltages on every pin. Then we can resume.

 

[nacho459]

I pulled out the tube and put it back in and it worked, I guess I had something wrong the first time I put it in, probably had grids mixed up or something.