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Vintage Tape (Audio), Cassette, Wire and Magnetic Disc Recorders and Players Open-reel tape recorders, cassette recorders, 8-track players etc.

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Old 17th May 2021, 12:59 pm   #41
ms660
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Default Re: Grundig tk 24

With Playback selected and no signal input measure the resistance between the input to c13 (junction of D1 and D4) and chassis.

Lawrence.
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Old 17th May 2021, 2:06 pm   #42
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Default Re: Grundig tk 24

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No sir every thing is ok no issue with Machanisum I tilted the unit i cant load spooltape due to gravity it will fall down if without tape; if I play pick up wheels rub the ground hence i removed main belt to stop the play machanical process My only aim is If bt out put comes with full volume then 100% i will get full volume with play back Head signal
Regards
Krishna
OK now understand. The TK 24 and similar Grundig TKs were designed only for horizontal operation. As you say if used vertically/upright the tape spools will fall off. Even if the spools were secured somehow, vertical operation would still not be good due to the flywheel not sitting down in its lower bearing.

David
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Old 17th May 2021, 2:57 pm   #43
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Default Re: Grundig tk 24

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With Playback selected and no signal input measure the resistance between the input to c13 (junction of D1 and D4) and chassis.

Lawrence.
I could not understand please clarify sir
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Old 17th May 2021, 3:02 pm   #44
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No sir every thing is ok no issue with Machanisum I tilted the unit i cant load spooltape due to gravity it will fall down if without tape; if I play pick up wheels rub the ground hence i removed main belt to stop the play machanical process My only aim is If bt out put comes with full volume then 100% i will get full volume with play back Head signal
Regards
Krishna
OK now understand. The TK 24 and similar Grundig TKs were designed only for horizontal operation. As you say if used vertically/upright the tape spools will fall off. Even if the spools were secured somehow, vertical operation would still not be good due to the flywheel not sitting down in its lower bearing.

David
yes sir
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Old 17th May 2021, 3:06 pm   #45
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Default Re: Grundig tk 24

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With Playback selected and no signal input measure the resistance between the input to c13 (junction of D1 and D4) and chassis.

Lawrence.
I could not understand please clarify sir
With the function control set to Playback and without any signal input from you're BT source measure the resistance between the input to c13 (junction of D1 and D4) and chassis with a multimeter set to measure resistance.

Lawrence.
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Old 17th May 2021, 3:18 pm   #46
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Default Re: Grundig tk 24

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With Playback selected and no signal input measure the resistance between the input to c13 (junction of D1 and D4) and chassis.

Lawrence.
I could not understand please clarify sir
With the function control set to Playback and without any signal input from you're BT source measure the resistance between the input to c13 (junction of D1 and D4) and chassis with a multimeter set to measure resistance.

Lawrence.
ok I will check it now and update
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Old 17th May 2021, 3:24 pm   #47
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Default Re: Grundig tk 24

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I could not understand please clarify sir
With the function control set to Playback and without any signal input from you're BT source measure the resistance between the input to c13 (junction of D1 and D4) and chassis with a multimeter set to measure resistance.

Lawrence.
ok I will check it now and update
sir it is open no value read either in on position nor in off position
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Old 17th May 2021, 4:32 pm   #48
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Default Re: Grundig tk 24

Next test, measure the resistance between connection 1 and connection 4 of the head as per the schematic with the Track switch set to D, the function selector can be set to Stop for that test but before that test can you confirm if relay W is being energized when the function switch is set to Playback.

Lawrence.

Last edited by ms660; 17th May 2021 at 4:44 pm. Reason: extra info
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Old 17th May 2021, 4:57 pm   #49
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Default Re: Grundig tk 24

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sir it is open no value read either in on position nor in off position
Just to be sure, what resistance range was your meter set to.

Lawrence.
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Old 17th May 2021, 10:16 pm   #50
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Default Re: Grundig tk 24

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sir it is open no value read either in on position nor in off position
Just to be sure, what resistance range was your meter set to.

Lawrence.
I checked in all range,ohms to K /sir just one thing clear me that I have removed c13 wire from selector switch and injected the signal directly to ef86 through c13 under this condition is it necessary to check head side wirings ?
Krishna
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Old 17th May 2021, 11:44 pm   #51
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sir it is open no value read either in on position nor in off position
Just to be sure, what resistance range was your meter set to.

Lawrence.
sir Already I checked this step, the problem is low volume in play back mode
please run attached video I think it will make easy to understand my issue

https://youtu.be/tPec0Seoowg

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Krishna
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Old 18th May 2021, 9:27 am   #52
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Default Re: Grundig tk 24

In the video are you saying that you've disconnect C13 from the head circuit and you are feeding a signal to the input side of C13 and that when in record the sound is good but when switched to playback the sound is weak?

Lawrence.
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Old 18th May 2021, 9:47 am   #53
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Default Re: Grundig tk 24

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In the video are you saying that you've disconnect C13 from the head circuit and you are feeding a signal to the input side of C13 and that when in record the sound is good but when switched to playback the sound is weak?

Lawrence.
Yes sir i could not under stand the issue audio amplifier is good no issue but why in playback audio is too low
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Old 18th May 2021, 9:55 am   #54
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Default Re: Grundig tk 24

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Quote:
Originally Posted by ms660 View Post
In the video are you saying that you've disconnect C13 from the head circuit and you are feeding a signal to the input side of C13 and that when in record the sound is good but when switched to playback the sound is weak?

Lawrence.
Yes sir i could not under stand the issue audio amplifier is good no issue but why in playback audio is too low
Still not exactly clear, are you saying the problem is with the amplifier in playback mode and not the head circuit?

Lawrence.
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Old 18th May 2021, 11:27 am   #55
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Default Re: Grundig tk 24

Quote:
Originally Posted by ms660 View Post
Quote:
Originally Posted by reartech View Post
Quote:
Originally Posted by ms660 View Post
In the video are you saying that you've disconnect C13 from the head circuit and you are feeding a signal to the input side of C13 and that when in record the sound is good but when switched to playback the sound is weak?

Lawrence.
Yes sir i could not under stand the issue audio amplifier is good no issue but why in playback audio is too low
Still not exactly clear, are you saying the problem is with the amplifier in playback mode and not the head circuit?

Lawrence.
I am not in a position to decide exact problem please guide
Krishna
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Old 18th May 2021, 11:53 am   #56
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Default Re: Grundig tk 24

The problem is that I don't fully understand what it is you're doing but at the moment I'm thinking that you have disconnected the head input circuit to C13 and replaced that input with a signal from your BT unit and that in record it sounds good and in playback it sounds weak?

If that's the case then the only part of the amplifier circuit that should alter when changing from record to playback is the feedback circuit between the two triodes, that's switched by relay contact W1, in playback the different components that are switched in are C10, R6 and R9, it might be worth checking C10 for leakage.

That's assuming that contacts B1 or B2 are not in the closed position due to whatever reason when playback is selected.

Lawrence.
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Old 18th May 2021, 12:14 pm   #57
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Default Re: Grundig tk 24

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Originally Posted by ms660 View Post
The problem is that I don't fully understand what it is you're doing but at the moment I'm thinking that you have disconnected the head input circuit to C13 and replaced that input with a signal from your BT unit and that in record it sounds good and in playback it sounds weak?

If that's the case then the only part of the amplifier circuit that should alter when changing from record to playback is the feedback circuit between the two triodes, that's switched by relay contact W1, in playback the different components that are switched in are C10, R6 and R9, it might be worth checking C10 for leakage.

That's assuming that contacts B1 or B2 are not in the closed position due to whatever reason when playback is selected.

Lawrence.
Ok thank you sir I will check and update
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Old 18th May 2021, 12:21 pm   #58
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Default Re: Grundig tk 24

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I'm thinking that you have disconnected the head input circuit to C13 and replaced that input with a signal from your BT unit and that in record it sounds good and in playback it sounds weak?
Lawrence.
That is exactly how I read the situation.

David
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Old 18th May 2021, 3:58 pm   #59
reartech
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Default Re: Grundig tk 24

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Quote:
Originally Posted by ms660 View Post
The problem is that I don't fully understand what it is you're doing but at the moment I'm thinking that you have disconnected the head input circuit to C13 and replaced that input with a signal from your BT unit and that in record it sounds good and in playback it sounds weak?

If that's the case then the only part of the amplifier circuit that should alter when changing from record to playback is the feedback circuit between the two triodes, that's switched by relay contact W1, in playback the different components that are switched in are C10, R6 and R9, it might be worth checking C10 for leakage.

That's assuming that contacts B1 or B2 are not in the closed position due to whatever reason when playback is selected.

Lawrence.
Ok thank you sir I will check and update
once again thankyou for support and valuable suggestions Now that problem solved its Capacitor issue i got same result in Record and play back also by connecting through Head but it is ran only for 30 sec ,afterwords the volume became low as it is ;but the change is it is same in Both mode, hence Now i checked ecc 81 voltages 2 volts i got for appropriate pins where as insted of 100/140 i got only 25volt when i remove volve ecc 81 voltage is as noted by diagram on load voltage drops please tell me is valve issue or some other issue
Regards
Krishna
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Old 18th May 2021, 4:29 pm   #60
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Default Re: Grundig tk 24

When the anode voltages are low what's the voltage measurements between pin 7 and ground and pin 8 and ground?

Lawrence.
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