[AMRadio] AMRadio Digest, Vol 118, Issue 7

rbethman rbethman at comcast.net
Sun Nov 3 11:05:08 EST 2013

It is detailed in the manual on page 43.

R9 MUST be unsoldered on one end.

The rest of the changes depend on whether the BC-939 is used, or not if 
a dipole is used.

The BC-939 Antenna Coupler has changes to be made when operating below 

A jumper must be placed inside it, and two fixed vacuum caps are also 

The jumper in the BC-939 takes one of the roller inductors out of the 

This is why I stated the operator's hesitation to just "toss" the BC-610 
into use on 160.

The manual specifically states that R9 will be damaged.

Its ratings make it hard to locate a replacement.

This TX is the only one that *I* know of that has to be modified to go 
on that band.

Then again, BC-610s aren't for everyone.  There are those that never 
manage to get one on the air.

They can be a pain.  It is satisfying to do so in my experience.

Bob - N0DGN

On 11/3/2013 10:42 AM, Mike Sawyer wrote:
> Bob,
>      I am not going to doubt you since you have the manual and I don't. We
> used the same MO and coil. He only went to 1880 with it because he wanted to
> shore up the MO drift and was limited by the temp. compensating caps in his
> junk box. If this is the jumper I think it is, it merely done by moving it
> out of the way. Can you elaborate a little? I have a British embassy rig
> that has the same requirement.
> Mod-U-Lator,
> Mike(y)
> ----- Original Message -----
> From: "rbethman" <rbethman at comcast.net>
> To: "AM Radio List" <amradio at mailman.qth.net>
> Sent: Sunday, November 03, 2013 10:36 AM
> Subject: Re: [AMRadio] AMRadio Digest, Vol 118, Issue 7
> Consult the manual, specifically the MC-109 modification.
> There is ALSO a component that MUST be jumpered to take it out of the
> circuit.
> The TU for 160, the PA Coil, and the fixed vacuum cap for such must also
> be available.
> Failure to install that jumper WILL destroy a component!
> The same applies when taken back off 160.
> It is thoroughly covered in the manual.
> My particular instance was having to modify the 2.0 to 2.5MC Tuning
> Unit.  By doing this mod, I can get down to 1.6MC.
> Bob - N0DGN

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