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Old 19th Feb 2017, 10:55 pm   #101
roverp6
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Default Re: Tandberg Huldra 8 valve failure

here is the continuity check with EF89 and there was no voltage readings on the base valve holder for pins #4 and 5, i only seem to get a voltage reading from 8 and 7 pins as described earlier. aside note when ef89 is in place the magic eye will move for station reception, valve removed magic eye stays in the widest gap apart. this may have no relevance i am just guessing.
clive
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Old 19th Feb 2017, 11:51 pm   #102
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Default Re: Tandberg Huldra 8 valve failure

Regardless of anything else you need to find out why there's no 6.3 VAC heater supply to the EF89. Trace the PCB tracks back from valveholder pins 4 and 5, taking voltage readings and looking for breaks in the tracks
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Old 20th Feb 2017, 1:20 am   #103
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Default Re: Tandberg Huldra 8 valve failure

The EF89 can be difficult to see the heater glow at the best of times. If the tuning eye works with it in but not with it out, that would suggest to me that it is working!
Are you sure you have the right pins when checking for the heater voltage? If you are checking from the top with the valve out and power on, the pins will number anticlockwise from the gap. If from below, they will be clockwise. Does the EF89 get warm if it is left on for 10 minutes or so?
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Old 20th Feb 2017, 1:49 am   #104
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Default Re: Tandberg Huldra 8 valve failure

i did notice when left on maybe 5-10 min there was some warmth to the tube and as you have said "hard to see a glow" i was expecting to see it glow in the same intensity as the others. here is the same picture that shows the voltage from the top, readings only from 8 and 7.

Clive
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Old 20th Feb 2017, 2:05 am   #105
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Default Re: Tandberg Huldra 8 valve failure

This makes no sense at all. Without a heater supply a valve cannot heat up or light up. There's something wrong with your measuring technique or your meter. Without reliable voltage readings it's very difficult to advise you.
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Old 20th Feb 2017, 9:37 am   #106
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Default Re: Tandberg Huldra 8 valve failure

Any chance of a picture showing the meter probes in socket's 4 and 5 of the valve holder and also showing the meter display/settings for that test?

Lawrence.
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Old 20th Feb 2017, 6:10 pm   #107
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Default Re: Tandberg Huldra 8 valve failure

I am new to the thread and as it is quite lengthy I thought a summary worthwhile:

1. The set worked for a while then blew the fuse
2. Various capacitors and diodes have been replaced
3. The set now has power again but there is no sound
4. The magic eye moves when the EF89 is in
5. The magic eye does not move with the EF89 out
6. EF89 Pin 7 (anode) = 222V, Pin 8 (screen grid) = 114V

I am not sure there is anything wrong with the radio section. Is the solid-state amplifier working? Have you tried the gram input?
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Old 20th Feb 2017, 6:17 pm   #108
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Default Re: Tandberg Huldra 8 valve failure

7. Establish if 6.3 AC volts present on EF89
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Old 20th Feb 2017, 8:05 pm   #109
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Default Re: Tandberg Huldra 8 valve failure

Points 4&5 indicate the EF89 is doing something and the EF89 is not used for AM reception so if that is not working the fault is not (just) the EF89. Priority is to determine if the audio amp is working.
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Old 20th Feb 2017, 9:40 pm   #110
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Default Re: Tandberg Huldra 8 valve failure

Is the O/P measuring to chassis from pins 4 &5 in turn I wonder?
This may account for no voltage indication if the heater supply is isolated from chassis?

Measure the voltage by setting the meter to ACV and placing one probe in pin 4 socket and the other probe in the pin 5 socket.

You should have heater supply around 6 to 6.5vac

Cheers
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Old 20th Feb 2017, 9:45 pm   #111
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Default Re: Tandberg Huldra 8 valve failure

Quote:
Originally Posted by Hunts smoothing bomb View Post
Is the O/P measuring to chassis from pins 4 &5 in turn I wonder?

This may account for no voltage indication if the heater supply is isolated from chassis?

Cheers
According to the diagram attached to post #87 one side of the heater is grounded.

In post #100 I stressed the need to measure the voltage between valve holder pins 4 and 5.
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Old 20th Feb 2017, 11:53 pm   #112
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Default Re: Tandberg Huldra 8 valve failure

quick reply i know i have screwed up some readings, me not using the right setting on the meter so i will address some of those shortcoming and the latest replies.............trying to do things when you too tired and not paying attention.

Clive
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Old 21st Feb 2017, 12:11 am   #113
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Default Re: Tandberg Huldra 8 valve failure

Quote:
Originally Posted by roverp6 View Post
Brief Update: put the new fuse in and capacitor plug in to the dim bulb tester. no flashes,smoke. the magic eye did move with signal strength on FM, that's the only band i used...........first noticeable observation no audio nothing even moving from record player and back to radio. one valve i noticed doesn't appear to light up all the other 4 do it is identified as EF89 see section of diagram were it is located, is it in he amplifier section? and how do you check for continuity? which pins. Thanks Clive
Can you confirm there is no sound even in Gram and AM, and in FM that the magic eye is responding to tuning. If so, the EF89 is not your problem. The fault now lies with the audio section. I have a German user manual but that's not much use to me, and the switching is very complex.

1. Check the tape button is not depressed as it probably passes the audio through the tape input/output.

2. Check the speaker selection switch.

3. Switch to Gram and turn up the volume. Is there any hiss or hum? Do you get any clicking sounds when switching between gram and other sources?
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Old 21st Feb 2017, 4:14 am   #114
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Default Re: Tandberg Huldra 8 valve failure

Quote:
Originally Posted by PJL View Post
I am new to the thread and as it is quite lengthy I thought a summary worthwhile:

1. The set worked for a while then blew the fuse
2. Various capacitors and diodes have been replaced
3. The set now has power again but there is no sound
4. The magic eye moves when the EF89 is in
5. The magic eye does not move with the EF89 out
6. EF89 Pin 7 (anode) = 222V, Pin 8 (screen grid) = 114V

I am not sure there is anything wrong with the radio section. Is the solid-state amplifier working? Have you tried the gram input?
to answer the questions above
1. the set was turned on twice since i got it ( i had it shipped from Norway), the second time for 10 min then flash from the inside of case.
2. only one capacitor C703 has been changed that was recommended by the forum.
3. correct no sound and set is running with power 120v
4. correct magic only moves when the EF89 is in place.
5. correct
6, my EF89 has 9 pins
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Old 21st Feb 2017, 5:39 am   #115
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Default Re: Tandberg Huldra 8 valve failure

It would seem that the EF89 is NOT at fault but the OP cannot give us the voltage readings. It is a red herring that the filament glow is not as bright as the other valves, but the valve is warming.
I think someone needs to move the OP on into actually finding the fault which will probably be in the audio circuit. At present we seem to be chasing smoke.
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Old 21st Feb 2017, 8:34 am   #116
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Default Re: Tandberg Huldra 8 valve failure

I agree with you 100% Sam.

The fact that the EF89 lights up and its presence or absence affects the observed behaviour of the set indicates that it has power applied to its heater.

However the OP has been unable to measure any voltage on the heater pins and I don't think he has tried to do so since being requested to check this again. This gives me no faith at all in any future readings the OP posts, especially where the reported voltage is zero.

I have done my best to help the OP, but little progress has been made since post #87.

Time for me to retire to the side lines and let fresh minds handle this one.
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Old 21st Feb 2017, 9:15 am   #117
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Default Re: Tandberg Huldra 8 valve failure

It seems to have a selector for front and rear speakers, could be incorrectly selected for present output.
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Old 21st Feb 2017, 9:42 am   #118
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Default Re: Tandberg Huldra 8 valve failure

Could it be something as simple as speakers plugged into the 'wrong' sockets - i.e. plugged into the rear speaker sockets with the selector set to 'front speakers' or vice versa. In addition dooes the OP realise that all 'E' series valves have 9 pins (after his comment 6 in post #114) following on from that, does he set his meter to AC Volts to measure the heater voltasge, connecting one probe to pin4 and the other to pin 5 of the EF89 or its socket.
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Old 21st Feb 2017, 10:56 am   #119
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Default Re: Tandberg Huldra 8 valve failure

Hi, roverp6 (I drove a 3500 one for quite a few years, be careful in the wet!). From my post 113 above.

1. Check the tape button is not depressed as it probably passes the audio through the tape input/output.

2. Check the speaker selection switch.

3. Switch to Gram and turn up the volume. Is there any hiss or hum? Do you get any clicking sounds when switching between gram and other sources?
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Old 21st Feb 2017, 11:04 am   #120
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Default Re: Tandberg Huldra 8 valve failure

Quote:
Originally Posted by 'LIVEWIRE?' View Post
In addition dooes the OP realise that all 'E' series valves have 9 pins
Not quite, a valve beginning with 'E' usually denotes that it has a heater voltage of 6.3 volts. The number '8' in the '89' part denotes the pin configuration I believe.

e.g.
EF91 has 7 pins, ECH42 has 8 pins, EF89 has 9 pins etc.

Cheers
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