hey guy`s
I bought a few portables 41-843 and a 42-842 both very similar electronic wise
will work on 42-842 first
and bought have same symptoms 117z6 tube lights up others stay cold not lighting
I replace electrolytics but not paper caps yet I don`t hear a sound dead silence tested speaker with 9v pops
if I put black test lead on terminal 4 every thing says 120v
if I put black test lead on terminal 3 I get nothing on any I did replace the ,05 cap
http://www.nostalgiaair.org/PagesByModel...013557.pdf
thanks sam
Oh NO not another portable!!!!
Just got though working on one very similar to this set Darn thing was making nutz!
Anyway on the back of the chassis you'll see a little slot where you plug in the ac line
cord for battery operation. Under the chassis behind the slot there is a big switch.
Use deoxit on it and plug in the plug in the slot several times.
On all of these AC/DC/Battery set( known as 3 way portables) the power supply
voltage are very critical. How it work is a small part of the HV from the rectifier tube
lights filaments in all of the other tubes. That filament buss needs to be at 9v or
slightly better. If not all kinds of stupid stuff happens. Not bad stuff but you'll be
chasing your tail trying to figure what the heck is wrong.
Check voltage at pin 8 of the 117Z6 (red lead) to B- black lead (where all of
the - side of the Ecaps go)
Should have 95 to 100vdc+ there.
Did you replace large capacitance low voltage Ecap that is in #47? Looks like 200mfd@25v.
That is the filter for the filament string. Also check #49 and 51 they are the voltage
divider for the filaments.
Replace the rest of caps.
Terry
ps the loctal tubes in this set will have a very dim glow and won't get hot at all.
terry
I replaced 5 electrolytic caps
replaced 49 resister bad with 2200
51 resister at 649 should be 680 little low but ok
cleaned switch
117z6 tube pin out as follows
1 not used
2 121v
3 121v note 2&3 connected
4 8.3v
5 120v
6 0.986
7 0
8 8.45v
thanks sam
What about p1 of the 1st 1LE3- to p8 of the 1LB4+. Should have 9vdc.
Terry
terry
p1 of the 1st 1LE3- to p8 of the 1LB4+ nope both at .0
switch bad ?
switch pin out voltages
1) .069 5) .069 9) .067
2) .043 6) .043 10) .720
3) .0 7) .0 11) .705
4) 121v 8 ] 121v 12) not used
thanks sam
Connect - probe to pin 4 of the battery/ac switch Then measure dcv on pins 1 and 2. Pin 1 should have about 100v pin 2 should be at 9v
Terry
terry
dcv on pins 1 and 2. Pin 1 should have about 100v pin 2 should be at 9v
pin1) is 72.5dcv
pin2) is 10.9dcv
thanks sam
Connect - probe to pin 4 of the battery/ac switch Then measure dcv on pin8 of the 1BL4 Should see your 10. vdc there. Check all 1.5 v tubes for filament continuity. That means check resistance between pins 1 and 8. all should show a low resistance like a few ohms. Check #48 and 46 could be a little high or you've got some bad paper caps pulling the HV down.
Cln tube sockets and replace the rest of the caps.
Terry
hey guys
I ordered caps from sal
but he does not have the .0003 @ 1000v and I`m not ordering from mouser for that just yet
what can I use for temp testing in place of it I don`t think it would ever see 1000v would it?
thanks sam
The reason why it has such a hv rating is because there are voltage spikes at the plate of the output tube. Don't think there is 1kv worth . Should be fine w/630v.
Terry
terry
ok thanks should have caps today
sam
If you like bring it over and we can knock it out.
Terry
hi terry
I replaced caps sunday but come down with cold did get little static but that was all
checked tubes on tester funny blew 3 out pretty blue light they were until I realized tester was blowing them
but ohmed the rest ok will get back to it
we can make a play date for april 11 or 12 wife going away yea
mike can join us but not kirk
sam
Can do Sunday working Sat. Am off the Sat b4 Easter.
Terry
Sam!
You are becoming Kirk.
You need to disassociate from him for a whie, he is a bad bad influence.
You are buying too much.
