a bit tighter

[g4rek]

Why is it that the if cores arent made stronger? i've broken yet another complete line up in my 706 mk2, they seem to snap even when i'm not using my full strength and always off tune which is very annoying. http://www.qrz.com/iB_html/non-cgi/emoticons/biggrin.gif

[wb6bcn]

One major problem isn't the cores, #it is the tools used. #There isn't an allen wrench that fits them properly. #You need to use the correct plastic tool. #In the service industry for over 40 years I have never broken a core that wasn't already cracked by someone else using the wrong, #or a worn out tool. #Not only is the proper tool required, #it needs to be fully inserted into the core.

They are made to a specific density, and hence are a particular hardness. #Under normal use they don't requied adjustment unless a frequency derermining part is replaced.

[K9STH]

It is a real "no no" to use a metal Allen wrench on coil slugs. Even if you don't break the slug, the metal will definitely have a marked effect on the frequency. As you remove the tool, the frequency will always increase in the tuned circuit becase ferrous type of metals will cause the frequency to go low. If you happened to use a brass Allen wrench (which are very rare), then the frequency would go lower because a non-ferrous material reduces the frequency of a coil.

Radio Shack / Tandy Electronics has several sets of plastic and nylon tuning tools at a reasonable price (not that cheap, but reasonable!). You really need to get a set from them or some other source. Those have no effect on the tuning and are much more "easy" on the slug material.

I have numerous types and sizes of tuning tools since I work on various sets manufactured from the 1920s onward. But, for "modern" sets you will only need a very few sizes and types.

Glen, K9STH

[WB2WIK]

Sounds to me like you ought to tighten the loose nut doing the adjusting. I'd recommend a monkey wrench with at least a 48" long handle, so you can put some weight into it.

[wb6bcn]

STH says:
</span><table border="0" align="center" width="95%" cellpadding="3" cellspacing="1"><tr><td>Quote </td></tr><tr><td id="QUOTE">. #If you happened to use a brass Allen wrench (which are very rare), then the frequency would go lower because a non-ferrous material reduces the frequency of a coil.
[/QUOTE]<span id='postcolor'>
Correct me if I am wrong. #

Brass, copper and aluminum cores are used in VHF and UHF circuits, #where the ferrite cores aren't desirable because the increase in the permiability factor is undesirable for that frequency range. #The non ferrous cores have the opposite effect in that they decrease the inductance as they are inserted into the coil.

[g4rek]

http://www.qrz.com/iB_html/non-cgi/emoticons/biggrin.gif Anyway they all need many turns clockwise to fully tighten them up, why isnt this done in the factory, I seem to have to do this on all my rigs, the bands seem awfully deserted these days dont they?

http://www.qrz.com/iB_html/non-cgi/emoticons/biggrin.gif Jim....g4rek..............

[K9STH]

For BCN:

That is basically correct. Also, the non-ferrous material has a lesser effect on frequency than does the ferrous.

For REK:

Back when I was in high school (late 1950s, early 1960s) and was working in K9BPV's TV shop repairing AC/DC broadcast band radios, there was one common thing that a number of radios were brought in for repair: The owner had found several &quot;loose screws&quot; and thought that they needed tightening! Of course these were the old type trimmer capacitors and the alignment was definitely &quot;screwed up&quot; by tightening these screws! But, that, along with a heater (&quot;filament&quot;) burning out in a series strung radio, kept me making $1.00 an hour or $1.00 per radio whichever was the greater (good wages for a high school student back then).

Glen, K9STH

[g4rek]

Yes having worked for many years as a bench engineer, thats not repairing benches incidently but all manner of equipment for various companies in the u.k. it s been quite rare for slugs to jam and even then there are methods that in some cases will get one out of trouble.
One manufacturer of marine equipment used to seal all the if coils with beeswax which became very hard after time, the only safe way to proceed was to place a small iron bit on top of the stuck slug for a time untill the heat transmitted down liquified the wax for a quick retune.
The smell of hot beeswax takes me back in time even now.............

[K6UEY]

We used to use a wand we called the dip stick it had a brass tip on one end and I think it was a lead tip on the other it was an insulated rod which you could insert into the coil and watch the swept response to determine if you wanted to go up or down in tunning multiple pole filters. Haven't seen one of those in over 30 years don't know if they are still around any more .
ENJOY!!! It is later than you know .......73, # ORV

[WB2WIK]

G4REK, yes, you're entirely correct, of course.

The bands are much deader now that we've all tightened down all our tuning slugs.

Speaking of slugs, don't the French saute them in butter and garlic and serve them as an appetizer? Oh, that might be snails instead.

While you're tightening down all the coil slugs, you might also consider tightening up on that timing belt in your car engine. If you make it very, very tight that's just perfect. When it breaks in two while you're driving, that's just the right amount.

WB2WIK/6

[wb6bcn]

</span><table border="0" align="center" width="95%" cellpadding="3" cellspacing="1"><tr><td>Quote (K6UEY @ Mar. 07 2003,02:40)</td></tr><tr><td id="QUOTE">We used to use a wand we called the dip stick it had a brass tip on one end and I think it was a lead tip on the other it was an insulated rod which you could insert into the coil and watch the swept response to determine if you wanted to go up or down in tunning multiple pole filters. Haven't seen one of those in over 30 years don't know if they are still around any more .
ENJOY!!! It is later than you know .......73, ORV[/QUOTE]<span id='postcolor'>
I used to have one of those. The one I had was made by GC, as I recall it was red. There was ferrite in one end and brass in the other end.

[K9STH]

I had forgotten those! It would be very easy to make one using some plastic rod from the hobby shop, a small diameter ferrite tuning core, and a brass screw. In fact, I think that I may just make one up tonight or tomorrow! It would come in handy when I am working on &quot;boat anchors&quot; for my clients.

Glen, K9STH

[g4rek]

Well Wb2wik,
I normally adopt the well well used practice of screwing things up till they snap and then backing it off a bit, this has always been my practice.
Timing belts, what a dreadful engineering disaster they are, how many times have you heard of a timing chain breaking? el cheapo is the word under the guise that its quiter than a chain and of course much cheaper my car a Escort mk2 has a duplex chain aint I happy, but the jeep has not it gets changed every 25,000 miles.The chain that is not the vehicle.... http://www.qrz.com/iB_html/non-cgi/emoticons/smile.gif