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Radiogram, no sound

rematzz

Sep 23, 2015
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i checked voltages with neg on chassis and pos on the intended area. voltage from pin 7 was 6.36V,from pin 3 it was 10.3V before i turned it off, it kept going up on that one.

i didn't check r40 because i can't find it
 

73's de Edd

Aug 21, 2015
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Look at the very bottom pictorial portion of my supplied information sheet and I have a RED B and D boxed, now, between them , find R39, then go up to 34
and then BAMMMMMM there is R40 within a FINE LINED GREEN box I have designated it with.
If those voltages are not up in the 100's of volts then another alternative is to place positive meter probe the pin 3 of the EZ80 rectifier tube,
since that is the very ORIGIN point of that voltage supply.

73s de Edd
 

rematzz

Sep 23, 2015
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i haven't found r40 yet because i haven't got much time today, but i did test the voltage on pin 3 of EZ80.
pin 3 of EZ80 is directly connected to the main power transformer on a tab labled HT. on pin 3 the voltage was alternating from and between 32.5mv to 35mv.
 

duke37

Jan 9, 2011
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The voltages you measure are absurd and I think you should get help for your own safety.

1. Take out the EL84 to protect it.
2. EZ80 Measure the AC voltage between P1 and chassis and P7 and chassis. Both of these should be about 225V AC.
3. Measure the
DC voltage between P3 and chassis, it should be about 289V DC.
4. if you are not getting the high DC volts, measure the AC voltage between P4 and P5 it should be 6.3V AC.

Get a supermarket trolley and bring the gubbins down the A1 to Derbyshire.:)
 

rematzz

Sep 23, 2015
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thanks for the safety warning.

i removed EL84 and turned on the set.
i tested p1 in AC it was alternating from and between 0.085v to 0.092v.

tested p7 in AC it was alternating up and down from 0.115v.

tested p3 in DC it was alternating up and down from 0.430v.

tested p4 with p5 in AC it was alternating from and between 11.83v to 12.3v.

i would bring it down the a1 but its too far for my trolly ;)
 

duke37

Jan 9, 2011
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Unplug the radio.
It looks as if your transformer is dead, Measure the resistance at the mains plug, You might get a resistance of about 100Ω.
Measure the resistance between P1 of EZ80 and chassis, also between P7 and chassis. A couple of hundred ohms would be expected.

I cannot understand the very low voltages yet double the correct voltage on the heater.
 

rematzz

Sep 23, 2015
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i have measured the resistance between chassis and pin 1 of EZ80, it came up with nothing.

did the same with pin 7 of EZ80, it started with 2.3M ohms and kept rising, it was 3.40M ohms when i finished.

i checked voltage of p4 and p5 of EZ80 it was 5.31V alternating up and down in DC, and the voltage in AC was about the same as last time and it alternating.

do you mean for checking the plug, to measure the resistance on the live and neutral prongs.
 

duke37

Jan 9, 2011
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When you say it comes up with nothing, do you mean that there was zero resistance or no connection?

As previously said (thanks Edd), if there is hum, it is most likely that there is high tension, over 200V. Yet you are talking about mV. Perhaps you have blown your meter possibly by measuring high voltage on a resistance range.

I am a bit of a crock so coming up to Pontefract by train with 3 hours travel and three changes would be arduous even though I could do with a day out. What else can I do to help?
 

Martaine2005

May 12, 2015
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What meter are you using? What settings?
Bob has given it to you step by step!.
If you stop to listen, and report back, it might be easier for me to follow this.:)
But really, please follow the instructions 1 by 1. You could easily kill yourself playing here.

Martin
 

73's de Edd

Aug 21, 2015
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Sir . . . "Razz-a-ma-tazzz"

O.K. . . . . .then, lets do this, put your VOM/ DVM ? in its ohms function, not its diode test function.

The set is now un powered and ,stone dead cold . . . .

Just wike you successfruwwy (EF)*, had tested the filament resistance presence on the pins 4 to 5 of the
tubes in that set, lets retest just one.

Matter of fact, just to confirm instrumentation,being in its proper settings and tube pin count familiarity, lets initially test across pins 4 and 5 of this sets Eazy 80 rectum-fire for its cold filament resistance.

Then . . . .with self esteem and towering confidence all built up . . .go ye forward to the pins 1 and 9 of the same Eazy 80
and see if some 10's or 100's ohms of resistance is not being present ?
If so, then keep one lead on either pin of the Eazy 80 and note that pin 3 of the sets EL84 Audio output tube has a 180 ohm ( brown-grey-brown color banding) resistor that goes to a common ground buss.
Use that common ground buss for your new position of the now free probe in hand.
If all is well in the transformer world, you will now have a resistance reading of about half of the amount that
you had read just before.
On confirmation of the above, you will then locate a 9V battery within the household and test and confirm all of the 9V DC level applicable ranges of the DC voltage function of your instrument.

Then you power up the set and use the DC metering range which would accommodate the reading of a 200-300 volt reading and use the PRIOR good known ground reference point for your metering negative ground probe and then see if a high DC voltage is not present on pin 3 of the EZ80 or 7 or 9 of the EL84.

If not ???????????

Get a test lead of approx 1-2 feet and its two clip ends and I will show you how to initiate a no instrumentation test of the PS and AF amp and 1st audio circuitry, my next trip back.


Pee Ess:
On your comment of the schematic . . . .I sent you the very,very best . . .newest . . . .for export . . .version . BUT . .apparently if you CANNOT find R40 on it, I need to pull out the old, first production run, version of that chassis that had used R27 as its schematic numbering. Its a 1500 ohm unit of 2-3 watts power rating.

I purposefully ration my time to 30 mins on the internet daily, so it will have to wait until tomorrow to UNITIZE it also.

* a . . .la . . . (Elmer Fudd)

I go now . . . . .CUL

73's de Edd


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rematzz

Sep 23, 2015
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thanks everyone for your help so far.

i tested the resistance of the set while it was unplugged last time, and it was unplugged for these tests.

i checked resistance of p4 and p5 of EZ80, the multimeter showed no reaction at all.

also on p1 and p9 of EZ80 there was no reaction from the multimeter.

its all looking a bit odd to me as i thought that there should have been something.
 

73's de Edd

Aug 21, 2015
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Sir . . . . . . . . . "Razz-a-ma-tazz"



also on p1 and p9 of EZ80 there was no reaction from the multimeter.

I knows why . . . . . it's cause it's being P1 and PSEVEN.
. . . . . .

i checked resistance of p4 and p5 of EZ80, the multimeter showed no reaction at all.

That means you have an open filament , no good EZ80 then . . . .

UNLESS you pull another tube nearby and test its 4-5 to verify that both your ohmmeter and yourself are both "ohmmicating " properly.

In which case, if then being successful, you would officially be the ohmmicat OR and it would be the ohmicat EE .

(Still wukkin' on yer NEW (old) first production run schematic.)
Its gonna be real PURDY, except for its being 63 years old . . . .and just how good looking can a 63 year old be ?


73's de Edd



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rematzz

Sep 23, 2015
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i just pulled EZ80 out and tested p4 and p5, the needle moved and it read 0 ohms but when i plug it back in, i get no reaction :confused:
 

73's de Edd

Aug 21, 2015
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Kind Sire . . . . . . . . .



Prithee, what type of meter doth thou be using, AND its brand and manufacturers model number.

Also, do think back, not too long ago, when your next block neighbor, Delmer A Dumbnuttz, was wanting to check out his air conditioner and borrowed it from you.

Then, three days later , called you up to ask what the difference was between volts and ohms ?

Then too, do also remenber the time, unbeknowingst to you, that your brother in law , Casper Pee Clodd , came by and your wife found your meter for him.
Then that afternoon, when you get home you get this call from him, asking what the expected voltage from his cars ignition plug wire should be ?

Now I ask you , have you checked out your meter lately, using a 10Ω-100Ω -1KΩ -10kΩ-100kΩ-1megΩ set of test resistors ? (###)
As well as my mention of a DC voltage check with a 1.5 V dry cell and the 9V battery.
Then do a series check of that nine volt battery passing thru a 100 ohm resistor and the metering of the resultant DC current ,
And a final AC mode check, by the measuring of your AC line voltage .
Only then . . . . . will you know if any of those prior knaves hath done a DASTARDLY deed unto your FINE instrumentation.

Some how, even with your erroneous readout of the Easy80's tube, I feel that you should now get in a dark (bathroom?)** and plug it in and
then observe all of those little glow worms and see if their filaments are ALL making ORANGE for you.

** SAFETY CAVEAT:

Steer clear and stay away from touching any plumbing, even though that set is a transformer model and not an AC/DC model.

Thasssit . . .

(###) Ohhhhhh ! ! ! . . .Ohhhhhhh ! ! ! Ohhhhhh ! ! ! Edd "lak's" the on page convenience/access to those little ohmmie thingies, and not having to take, an otherwise
l o o o o ng circuitous path of having to shift to Symbols Font Cap W.

73's de Edd


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rematzz

Sep 23, 2015
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I've stopped using the meter and started doing all the tests all over again today.
The multimeter i am now using is a digital meter and its called ISO-TECH model number is IDM69.
I unpluged EL84, put the negative probe on chassis and positive on p7, i measured it in DC and the multimeter screen just flashed.
I put EL84 back in and measured voltage in DC, negative probe on chassis and positive to p7,it measured 6.5V and kept rising.
Measured p9 in DC on EL84 with negative probe on chassis and positive to p9, it measured 213.5V and kept dropping.
I measured both sides of r27 in DC and negative probe on chassis and positive to r27, one side measured 356V and the other was 308.5V.
I measured AC voltage of EZ80 on p1 with negative probe on chassis and positive to p1, it was 291V, i did the same with p7 and it was also 291V.
I measured AC of EZ80 with one probe on p4 and one on p5, it measured 6.85V.
I measured DC of EZ80 with negative probe on chassis and positive to p3, it measured 360V.

I unpluged the set and measured the resistance on EZ80, with one probe on chassis and the other on p1 it was 169.7 ohms.
I did same on p7 it was 161.6 ohms.
Checked resistance on p4 between p5 and it was 00.4 flicking to 5 and flicking back again.
Checked resistance on p1 between p7 and it was 0.332k ohms.
Checked resistance on chassis and p1 of EZ80 and it was 173.6 ohms.

All valves light up orange and EL84 was so hot after i turned it off that i burnt my hand and that was about 5 mins after turning it off.
 

Martaine2005

May 12, 2015
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They sound much better values. Seems like the meter was faulty or you were reading it incorrectly.

Over to you Bob and Edd.
I am following this thread as I want to learn about valves too..

Martin
 

duke37

Jan 9, 2011
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I think I may have been renamed Bob.
Valves are not much different from fets but they bite much better.

I have not checked the voltages with the published values but they look right.
The EL84 is a power valve and does get hot but if the capacitor feeding the grid is leaky, then the valve will pass too much current and the valve and other components can fail.
The current can be checked by measuring the EL84 cathode voltage, if it is much over 7V then the capacitor feeding the grid MUST be changed. Use ohms law to calculate the current from the voltage and resistance. You could check the value of the cathode resistor but make sure that the set is disconnected from the mains and that the cathode capacitor is discharged before connecting the meter.

Trevor
 

duke37

Jan 9, 2011
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Adam

A rose by any other name would smell as sweet.;)
I have been called an old fart!;)

Trevor
 
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