[ARC5] My 10 meter BC-454...

[Kenneth G. Gordon]

Thank you, Richard. Your method sounds superb! I have MEK here too. 

Ken

On 23 Jan 2013 at 22:33, 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
> 
> 
> 



Kenneth G. Gordon W7EKB

"Courage is being scared to death but saddling up anyway."--- John   Wayne