Sourcing tuner string(s)

[HRmeteohub]

Hi there!

I just read that someone here on the forum had burned tuner string. I do have one GF-8080 that hasn't got tuner string. I have looked for that kind of string (AKA radio/tuner dial cord), but could not find it locally.
Of course, there are some on ebay for about $4-$10, depending on the source. Do you know what is the best source for 70 cm (2 ft) of string?
Thank you!

Edit: MyOhMy sent me a link with one from UK, and there is also one from Serbia. There are other, more expensive sellers on ebay.

 

[Fatdog]

When looking for dial cord, the most important thing is you want the new cord to be as close in diameter to the old cord. That way, the needle will likely land on the correct number when tuning.

Here's a site selling 7.62m for only $4.50. I don't know about shipping though.


Other options that have worked for others:

- Dental floss
- #6 bead string (found at craft / fabric stores)
- Gorilla brand fishing line
- Nylon cord lightly coated in rubber cement

 

[HRmeteohub]

Thank you, that I did not know.

 

[HRmeteohub]

I have changed the string on my GF8080 and it slips. Actually, I tried with dental floss (thick one), and above mentioned string and they both slip at the one end of the scale. Basically, I can tune all stations from 90-108MHz, but if I set it to 88MHz, it stays 'there'.
I have tried hooking it differently, using more force, but to no avail.

Unfortunately, my experience with tension of tuning cords and proper length for this 8080 is lacking. I believe that I had routed the string properly, but I can't get the SM to check. I must have been doing something wrong.
Do you people have any advice on what should I try next?

 

[Fatdog]

How do you have it anchored back at the main dial? It should look something like this:

(NOTE: This is not the actual tuner dial for the GF-8080 - it is used as an example)

 

[BoomboxLover48]

I have changed the string on my GF8080 and it slips. Actually, I tried with dental floss (thick one), and above mentioned string and they both slip at the one end of the scale. Basically, I can tune all stations from 90-108MHz, but if I set it to 88MHz, it stays 'there'.
I have tried hooking it differently, using more force, but to no avail.

Unfortunately, my experience with tension of tuning cords and proper length for this 8080 is lacking. I believe that I had routed the string properly, but I can't get the SM to check. I must have been doing something wrong.
Do you people have any advice on what should I try next?

GF-8080-TuningString.JPG

Please don't use dental floss! Yuck!

On the tuning pulley it should have a definite number of turns. This gives enough friction to grab on it. If the cord is thick one it might make only 3 turns when it was designed to have a thinner cord with say 6 turns on the tuner pulley.

So the thickness of the cord is very important when the tuning pulley is less wide. Number of turns and spring tension is another factor to take into account.

Over these years I've put tuning cords on so many boomboxes, tube radios and receivers, it can become tricky in some cases but the cord should grab well on the tuning pulley. The last cord replacement I did was on GF 777 and Rising 20/20.

 

[floyd]

If all else fails you can use a tuner string idler pulley from a junk box just mounted in a place where you can put tension on the string.

 

[HRmeteohub]

Sorry BL48, I have used the clean, new, non-waxed DF just for test. Besides, it did work just as this string.

Basically, it goes nicely until it reaches this point, at about 90MHz on the scale

Now from this position it does only goes to the 88MHz (left), but it will not move back towards 108MHz.

Another detail...



Arghhh! Got it!

Just as I was shooting and preparing photos, I got the idea looking at this mechanism. The string/cord is going at 88MHz position over the pully at "downwards" angle, pushing the "needle" to scale base (aluminum) plate. This causes a bit more friction than on the other parts of the scale, and makes it harder to move.
I cleansed it a bit, than took some silicone oil, put a dab on the scale base, just under the needle where it touches the aluminum plate, and it helped!

I'll let you know if this works on the long run, but for now it is okay.

 

[Fatdog]

Super yay!!!! Sometimes it is good to step away and revisit later with a new eye.

 

[BoomboxLover48]

Increase the tension on that spring.....that is it!

That spring is in compressed state!

 

[TW5]

string on tuner pointer might not be right
should be more like this
does not seem to be level and tightens up near the ends.

 

[HRmeteohub]

Well, I do agree with you, it would be better, but this is the way it was routed back in 1977. This is clearly depicted on all images. However, cutting this small, 40 year old piece of plexy is not appealing to me. I appreciate your effort of editing and posting the picture to make your (valid) point. Thanx.

As far as putting more tension goes, I tried (but did not make a photo of that position), but nothing changed.

At the time, I was concerned that the old string wore out grooves too deep and now the new string is getting too much friction on them. I think I had a photo of the grooves somewhere...

 

[TW5]

you may need to switch the spring to the other string
this might let the string move more
and let the spring stretch
can quite see which string is which from the pictures