[ARC5] on sticking coil windings together - Re: My 10 meter BC-454...

[John Hutchins]

Group
Subject on sticking coil windings together.  E6000 sewing glue, yep that 
is the one.  Look it up some one did some home analysts and found that 
this glue had little effect, in degrading a coils Q better than varnish, 
better than many materials .

www.qsl.net/k5bcq/COIL/COIL.html

With all that cold -50 below weather up north that would have been a 
great opportunity to test in extreme cold for free! to see it the low 
temperature had any effect using 2 coils of known inductance, one free 
air and one wrapped and glued.  I know in -50 below I would change Q in 
a hurry.
Later
Hutch

On 1/24/2013 12:33 AM, Richard Knoppow wrote:
>
> ----- Original Message ----- From: "Kenneth G. Gordon" 
> <kgordon2006 at frontier.com>
> To: "Leslie Smith" <vk2bcu at operamail.com>
> Cc: "ARC-5 List" <arc5 at mailman.qth.net>
> Sent: Wednesday, January 23, 2013 9:31 PM
> Subject: Re: [ARC5] My 10 meter BC-454...
>
>
>> On 24 Jan 2013 at 16:21, Leslie Smith wrote:
>>
>>> Ken,
>>> Speaking generally, stability diminishes with the square of the
>>> frequency, so IF a 3 to 6 MHz receiver is stable within (say) 4 KHz at
>>> 3MHz,
>>
>> Actually, it is much better than that.
>>
>> BTW, in this case, by stability I meant "mechanical" stability: i.e., 
>> if you tap
>> on the case, it wobbles. The HFO winding is floating in this 
>> abomination.
>>
>> I'll fix that tomorrow. What I will probably do is to completely 
>> rewind all three
>> coils. When I finish with them, I'll glue them down so they won't move.
>>
>> Also, according to the original article, the original tuning slugs 
>> are supposed
>> to be put back in the coils after they are modified. That has never 
>> been done
>> for this one. Therefore, it won't tune below 28.2 MHz, but will tune 
>> up to 40
>> MHz., and the antenna trimmer is supposed to be about centered at the
>> high-end of the band, but it is fully meshed instead. Obviously, the
>> inductance of all the coils is too low.
>>
>> Ken W7EKB
>>
>     I don't know what you plan to glue the winding with but I 
> discovered that its easy to make home-made Q-dope.  I dissolve 
> Styrofoam, from cups of shipping material, in MEK. I think Xylol also 
> works. Use pure white foam, drinking cups work well. Crumble them and 
> let them soak in a glass container filled with the solvent. They will 
> dissolve very quickly at first and more slowly as the solvent reaches 
> saturation.  I stopped when the mixture was about the consistency of 
> honey.  The dope takes several minutes to set. You have enough time to 
> maneuver things. I think full hardness is reached in perhaps half an 
> hour or a more.  The finished dope should be uncolored and not cloudy. 
> It may need to steep for several days to become fully cleared.
>     I tested my dope on home made coils on a Boonton Q-Meter at 
> several high frequencies (up to about 250 Mhz). I wound the coils on 
> thin cardboard tubes (from toilet paper). My coils had very high 
> initial Q and the Q showed no change at all when covered with the dope.
>     Q-Dope is still manufactured but may be hard to get and I am not 
> sure of whether there are restrictions on shipping (you can ship 
> anything if you are willing to pay for it). This stuff is easy to make 
> and very cheap. You do need a _glass_ container with a lid that is not 
> affected by the solvent.
>
>
> -- 
> Richard Knoppow
> Los Angeles
> WB6KBL
> dickburk at ix.netcom.com
>
>
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