[Boatanchors] E.F Johnson calibrator 250-28 tube?

[Bruce Ussery]

The mystery tube tests fine in the TV-7D/U as a 6BH6, and a spare 6BH6 works 
fine in the circuit. A 6AU6, also a sharp cutoff pentode also seems to work 
fine. I guess all it has to do is make the circuit oscillate, and the duty 
cycle will always be short. This radio is going back in its cabinet.

Thanks all,
Bruce

----- Original Message ----- 
From: "jeremy-ca" <km1h at jeremy.mv.com>
To: "Bruce Ussery" <twc9198764412 at earthlink.net>; 
<boatanchors at mailman.qth.net>
Sent: Monday, December 10, 2007 10:08 PM
Subject: Re: [Boatanchors] E.F Johnson calibrator 250-28 tube?


> Mine has a 6BH6 and is also in a HQ-140X. I also like the Hammarlund 
> tuning and the great bandspread.
>
> Carl
> KM1H
>
>
> ----- Original Message ----- 
> From: "Bruce Ussery" <twc9198764412 at earthlink.net>
> To: <boatanchors at mailman.qth.net>
> Sent: Saturday, November 10, 2007 8:37 PM
> Subject: [Boatanchors] E.F Johnson calibrator 250-28 tube?
>
>
> I recently brought an HQ-140-XA back to life. The more I play with it the 
> more I like it's smooth, accurate tuning and good audio. A previous owner 
> added a 100 kc crystal calibrator (and did a neat job), but it's not the 
> XC-100 model that is mentioned in the manual. It's an E. F. Johnson 250-28 
> which looks pretty similar. It's working OK, but the tube number is 
> scraped off. If it croaks (probably not in my lifetime), I don't know what 
> to replace it with. My usual searches revealed to details of this unit, 
> only that it exists is other hams shacks. So-- does anyone have one or 
> know what the tube is? I promise to add a nice label for the next owner.
>
> Bruce
> WA4ZLK
> _______________________________________________
>