• The move to the new server is done. There are some software and database maintenance updates in process. This has us passing the hat around to help out. We appreciate any donations. Seriously, even a dollar helps. The payment page may be found here - https://www.audiokarma.org/support.html

6e5 magnavox tuning eye help

Tubeglowpio

Tubeglowpio

Active Member
Hey guys, about to fire up my new Magnavox Berkshire console but need help figuring how to install the 6e5 tube not sure what pin 1 is on the socket and tube, think it may have been in wrong before when I got it maybe. Will post pics soon.
 
Register to hide this ad
So got her up and running somewhat last night, Received some AM stations last night but FM was dead, now AM doesn't work either. Power amp works now, eye (tuning eye circuit had a bad resistor) and lights are good. It has all new tubes and changed every cap except the domino caps so that is suspect, console is rated for 205 watts and I was only pulling about 85 watts through the dimbulb tester with variac, for the dim bulb I had a 200 watt bulb and it lit up a little bright about as bright as a 1 or 2 watt bulb so something might pulling extra current, although wouldn't watt meter read higher then? I'm going to have check tuner voltages and change out those domino caps most likely, any other ideas? Sure hope the IF transformers are ok.
 
Be sure you are using the correct socket for the 6E5. There is a resistor inside the socket before any wires get connected externally.
 
cademan said:
Be sure you are using the correct socket for the 6E5. There is a resistor inside the socket before any wires get connected externally.
Click to expand...
I put a new 6E5 in and replaced a burned up resistor in the circuit and the Eye is working good now, only real problem left is the AM and FM are both silent (dead).
 
:idea: Don't know if you did something inadvertently. You will probably need to check a resistor or two. Its most likely the IF cans are fine.

EDITED so don't publicly quote my earlier reply.
 
Last edited:
cademan said:
:idea: Don't know if you did something inadvertently. You will probably need to check a resistor or two. Its most likely the IF cans are fine.

EDITED so don't publicly quote my earlier reply.
Click to expand...
maybe, but this thing was dead when I got it, think I must have a missed a bad domino cap and maybe a resistor, there isn't much else to be wrong at this point.
 
The last completely dead Magnavox tuner I fixed had an open resistor between an IF can and the tube. No plate voltage, so no signs of life. Might be worth a quick voltage check on the various tube pins along with a clean and re-seat of all tuner tubes if you haven't done that. I've had a lot of "dead" tuners that were just crusty connections too.
 
gadget73 said:
The last completely dead Magnavox tuner I fixed had an open resistor between an IF can and the tube. No plate voltage, so no signs of life. Might be worth a quick voltage check on the various tube pins along with a clean and re-seat of all tuner tubes if you haven't done that. I've had a lot of "dead" tuners that were just crusty connections too.
Click to expand...
I checked wiring continuity and resistor values for most of the amp and tuner but of course it's going to be one of the ones that looked great. What's the best way to clean out those really small hole tube sockets? I have a kit for normal 9 pin and octals. The amp sounds pretty good but slightly muddy, no distortion or hum, I think the open back and high freq rolloff plays a roll in that. Also the dim bulb limit it to around 80 volts so I'm sure it will sound better at 120v, just want to double check everything and fix the am/fm before removing the bulb from the line. The whole console is drawing 1 amp at 80 volts so far.
 
I am stumped as to why my line is so low and it's only drawing 1 amp yet bulb is a bit on the bright side. So I would think that if I had a short my voltage would sag a bit but also my current should be higher as well. Any thoughts before I pull it back out this weekend?
 
Inter-dental brushes work great. They're meant for sticking between your teeth in place of floss. 7 and 9 pin sockets use the same pins.

try it with normal voltage. Low voltage on the oscillator section of the tuner can make it not work, especially if the tube isn't 100%. If the bulb isn't full bright and current ls under 1 amp, you're fine.
 
gadget73 said:
Inter-dental brushes work great. They're meant for sticking between your teeth in place of floss. 7 and 9 pin sockets use the same pins.

try it with normal voltage. Low voltage on the oscillator section of the tuner can make it not work, especially if the tube isn't 100%. If the bulb isn't full bright and current ls under 1 amp, you're fine.
Click to expand...
The bulb is not full bright for sure but still brighter than I'm used to and I wouldn't think that it would effect my voltages as much as it is. My plate voltage on my 6v6 was only around 230 and is spec for 300 so even with a bulb in line dropping some voltage that seems low. I'm going to check all voltages this weekend and hope to have it all sorted out. I do love how nice this thing looks all lit up. I have not seen another one of the in ebony with the clock/timer.
 
What size bulb? If its less than 100, its not enough. With an amp and a tuner you probably need closer to 150w honestly. At this point if nothing is getting hot, I'd just plug it in.

If you have 80 vac in, you're at 68% of normal run voltage. 230v on the plate vs a 300v spec is 77% of normal, so you're actually higher than it should be all else being equal. Not unexpected though, the tubes will not conduct as well with low heater voltage so I wouldn't worry about this at all. Those voltages also typically have a 15% tolerance anyway.

Its not the output section that will bother this, its the tuner. Low voltage in the output might add some distortion but overly low in the tuner can just shut it down. The oscillator tube needs to be in reasonably good shape, and even a strong tube may not run properly at ~70% heater supply.
 
I'm using a 200 watt bulb, I just though it was weird that the 200 watt bulb was dropping 40 volts to the primary and the bulb is brighter than when I've repaired any other tube stereos, which have mostly been under 12 watts or so output though. I didn't smell anything burning and no plates were red plating so maybe I'll just bring her up slow with the variac and see.
 
gadget73 said:
What size bulb? If its less than 100, its not enough. With an amp and a tuner you probably need closer to 150w honestly. At this point if nothing is getting hot, I'd just plug it in.

If you have 80 vac in, you're at 68% of normal run voltage. 230v on the plate vs a 300v spec is 77% of normal, so you're actually higher than it should be all else being equal. Not unexpected though, the tubes will not conduct as well with low heater voltage so I wouldn't worry about this at all. Those voltages also typically have a 15% tolerance anyway.

Its not the output section that will bother this, its the tuner. Low voltage in the output might add some distortion but overly low in the tuner can just shut it down. The oscillator tube needs to be in reasonably good shape, and even a strong tube may not run properly at ~70% heater supply.
Click to expand...
So I removed the bulb from the line and things did improve, primary is at 120v and I did receive a few channels on both am and fm, but they were weak. I'm sure part of that is just that it needs an alignment. I feel like my volume doesn't get to normal levels till about noon, yet if I plug my phone straight into the power amp section levels seem fine, volume pot doesn't have any dead spots or static though so something must be off in the preamp section.
 
You must log in or register to reply here.
Back
Top Bottom