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Lineair

Dear Friends

This set was given to me by one of my friends. The only problem is with the dial cord. Both the pointers are controlled by a single knob.The shaft moves the flywheel and two clutches have been provided for the AM/FM bands. When the FM band is pressed the FM side clutch gets engaged and the AM band clutch gets disengaged thus providing movement to the FM pointer drive. Same is the case when the AM band is pressed. Here the FM clutch gets disengaged and the AM clutch gets engaged. My problem is that both the clutches are slipping. When the FM band is pressed the FM pointer does not move. When the AM band is pressed The pointer only moves 50% and again the clutch starts slipping. What is the correct way to adjust the clutch system? There is no jamming in the mechanical system.
I shall be grateful if somebody can help me in solving this problem.

Regards
P.Rajan

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The only solution is quite a laborous job.
Clean the whole mechanism from sticky lubricant and lubricate with thin oil (e.g. sewing machine oil)
You did not mention the exact type so I have to guess about the friction material of the clutches. Clean it and work it up a bit with sandpaper; take care that it stays free from lubricant. That is somewhat critical because the shifting part must be lubricated
Nico

--
een kinderhand
is ook weer gauw leeg

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Dear Mr.Rajan,

Please look at this toppic:

--
Cees PA1DBA

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Dear Mr. Nico/Goldline

Thanks your reply. Yesterday I tried to adjust the position of the lever which pushes the AM/FM pulleys which make contact with the flywheel. I also tried to adjust the position of the flywheel. When the FM/AM band key is pressed there is a lever mounted on the shaft which rotates when the band switch button is pressed and this rotation of the shaft gives movement to the lever which in turn engages/disengages the two AM/FM pulleys and vice-versa. After the pulleys are pushed and after the band key is fully pressed a small gap is produced between the pulley and the lever to ensure that the pulley rotates freely without rubbing the lever. I carried out the adjustment so that I was able to get the same gap in the two levers when either of the AM/FM keys were fully pressed. Earlier this gap was not uniform. Now the result is that the FM dial cord system is working correctly but the AM pulley slips. May be the friction material is worn out. I would like to take the dismantling job as a last resort as it is quite complicated. Before dismantling the shaft and pulley, both the dial cord will also have to be removed and putting it back itself is a difficult task.
Is there an easy method to change the friction material with carrying out dismantling? I am in India and I do not know what type of material is to be used?

Regards
P.Rajan

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Hi Pandu;

I know this problem and i have done many replacements of this friction materials without dismantling the complete unit.

The replacement friction material i buy in a local handy shop, they sell round felt pads wich have a sticker ( with a paper protector on it ) on one side, these pads are sold to stick on furniture and small objects ore other items so that they don't scratch the furniture etc. They sell these with different thickness and sizes.
I use one with about the same size like the original. ( Mostly they are sold in a plastic bag with several on 1 page )

Then i punch a hole in the center of this round felt pad ( about 6 a 7 mmm ..this is for the center axis )

Then with a cissor i cut from the side to the hole ...so only a cut to the center..not completly in half.

Then i loosen the screws of the flywheel and the clutches to make some space to work.

Then with a screwdriver and a small knife i remove all of the old frictionmaterial and clean it with a alcohol ( ipa ) as clean as possible.

Finaly with a pointy-nose pliers or using tweezers i can place the new pad in place ( first remove the paper protector from the sticky site )

Finaly, reajust the spacing....Job done !

Succes.... Greetings Dirk

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Dear Mr. Dirk

Thank you very much for your reply. You have given the perfect solution to this problem. But before I proceed I have some queries to ask.
The felt tape which you have described I presume has the adhesive only on one side. But here the foam tape which is available has got adhesive on both the sides. Tape with one side adhesive is not available.So when I remove the friction material and try to fix this tape it will adhere to the pulley on one side but it will also stick to the flywheel on the other side. To avoid this I will have to stick a non adhesive piece on one side. This will increase the total thickness. So please let me know the following:
1. What will be the approx. final dia of the felt piece which will get fixed to the pulley?
2. What will be the approx. thickness of this felt piece?

Thanks and Regards

P.Rajan

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But here the foam tape which is available has got adhesive on both the sides. Tape with one side adhesive is not available.

Pandu,

You don't need foam tape but felt pads.

[image]

Regards,

Wil

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Dear Mr Wil/Mr.Dirk

Thank once gain for your all your advice. I have solved the problem now. I carried out the solution as follows.
I again carefully observed the friction material. I noticed that the thickness of the material on the FM pulley was around 2-3 mm but on the AM pulley it had become nearly 1mm. So I cut a felt piece 30mm in Dia and made a hole in the center of about 8mm. Then as per your advice made a slit only on half the portion till the center. Now Without using any Adhesive I just inserted this piece between the existing friction material on the AM pulley and the flywheel. Now the AM dial cord drive is working perfectly.
On trial of the set I am facing some problem with the volume control and this I am posting in a separate thread.

Thanks
Regards

P.Rajan

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Dear friends

Now I am facing this problem in the above set.
All the bands are working correctly. But even with the volume control at minimum position the actual volume is quite high. Specially in case of the FM band this is too high. Before I do further checking I have some queries to ask.

1. On The radio set there are 4 potentiometers for the tone control and one for the volume control. But the schematic shows 6. Which is this sixth one?
2. As the schematic is in German language and no component layout drawings I am unable to distinguish the various potentiometers.
3. The pots. are as follows:
a. R50 - 1K - 1.8Khz
b. R51 - 1K - 3.5Khz
c. R42 - 100K - B
d. R31 - 5M - B
e. R34 - 2M - L
f. R30 - 5M - H

I Presume that R34 is the volume control but unable to distinguish the others?
What is the use of the switch "S" and where it is located?
I presume the switch "FA" is used to connect/ disconnect the internal antenna for the AM bands. Is it correct? Is it operated by the big Knob on the left side?
I shall be grateful if somebody can help me in solving above problem.I am asking these questions because the component layout drawings of the above radio set are not available.

Regards

P.Rajan

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Dear Mr. Rajan,
Can you post a copy of your schematic diagram here, so we all can think with you?

The switch S is a audio-mute contact and triggerd by the off switch.
FA = ferroxcube antenna (internal MW antenna)
R34 = volume with loudness taps
r50/51 are part off the 4 gang equalizer

and r30/31/42 are not clear about there function...

--
Cees PA1DBA

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Dear Sir

As desired by you I am attaching the 2 pages of the schematic which I am using.

Regards

P.Rajan [image] [image]

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Hi;

I have a question for you...;is the chassis still in the housing and are the original speakers still connected like they should?

I'm asking this because i once had the same problem like you with a Grundig radio, i was testing and reparing the radio out of the housing ( like i allways do ) and then i'm using a remote speaker connected on the auxilary speakeroutput connectors on the back of the chassis.

Sometimes there is a feedback line that is wired trough the connectors of the speakers, so if you remove the radio out of the chassis it's possible that the feedback isn't working anymore.

There can be a lot of different faults wich can have this effect.

I hope that you allready have recapped the complete radio? All the ERO & Wima capacitors realy have to be replaced.

Succes....Dirk

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Dear Mr. Dirk

The above set was imported by one of my friends from Germany.The set has been fully restored and all the capacitors have been replaced including the main filter capacitor 50ufd + 50UFD. All the bands are working correctly and the set is in excellent working condition. The sound quality is superb. The only problem was with the dial cord. It was given to a local technician for solving the problem but he was unable to understand the system and he could not do it. I have solved the problem and have given the details in my earlier postings.Now both the dial cords are working correctly.
In India valve sets with FM were never manufactured. FM transmission came to India very late and the valve sets manufacturing was stopped after 1972/73. So this type of problem was never faced in India. Some time back I restored a Telefunken Concertino radio set of 1961 but in this set the FM and the AM bands are Tuned by separate knobs and hence this type of problem was not there.
For me also it took some time to understand the mechanical system.
Now the only problem is the High volume even when the volume control is in zero position. This is more noticable in the FM band where the gain is quite high as all the stations are local.I have checked the volume control R34 and it is O.K. the resistance R35 390 ohms is also O.K. The ground connection of R35 is also O.K. Can this problem be due to the valve EABC80?
For the time I do not have this valve in spare as this valve was never used in Indian radio sets. I think because of the resistance R35 there will be some signal voltage even in zero position of the volume control.

Regards

P. Rajan

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Can this problem be due to the valve EABC80?

yes, it can, this is a well-known problem

--
http://www.hupse.eu/radio

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Dear Mr. John Hupse

Thanks for the reply. Yes I have confirmed that this problem is due to the valve EABC80. I slightly shifted the position of the valve and the problem is solved. As the socket is o.k. and all the connection to the socket are also o.k. I presume some thin wrong with the valve. I have to wait till I get a spare valve and recheck.

Thanks once again to all

Regards

P.Rajan

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When you remove the grey wire on the secundairy of the output transformer, will the volume control work better ?
I am thinking about a positive feedback instead of a negative feedback due to a wire
misstake .

--
Cees PA1DBA

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