[ARC5] BC-455 IFT - measurements

[Mike Feher]

I agree, it is pretty loose. Regardless, if the secondary resonates with the
12SK7 interelctrode capacitance, plus a few stray pfs here and there, it
would be about 1 MHz. I have not measured the self-resonance, which may be
even lower. So, it is really just acting as a high impedance broadband input
to the grid. 73 - Mike 

Mike B. Feher, N4FS
89 Arnold Blvd.
Howell, NJ, 07731
732-886-5960 


-----Original Message-----
From: ARC5 [mailto:arc5-bounces at mailman.qth.net] On Behalf Of
kgordon2006 at frontier.com
Sent: Wednesday, October 29, 2014 3:28 PM
To: Dennis Monticelli
Cc: ARC5 at mailman.qth.net
Subject: Re: [ARC5] BC-455 IFT - measurements

On 29 Oct 2014 at 10:58, Dennis Monticelli wrote:

> Perhaps someone can comment upon the degree of coupling between the 
> two coils.  If the coupling is tight, then the capacitance's on both 
> sides will interact.  Adjusting one side will pull the other side into 
> pretty much a single resonant circuit.  Perhaps that was what was
intended.

Dennis:

In my opinion, the coupling is pretty loose, but I have no way to quantify
that at this point. 

What I will do is to take a close-up photo of my 7277 IFT with the cover
removed, and with a tape-measure along side of it so you can see the
distance between and the orientation of the two coils.

Then if you would give us your opinion of the coupling, I would be grateful.

vy 73,

Ken W7EKB
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