[HBR] HBR from Heath HR10B Question

[Steve]

Walt

Thank you so much for helping me not make a big mistake.  I did a quick 
comparison of a couple of the key elements.  The cap in the HR10 looks 
like it fits the bill, the SX140 cap will not.  The chassis of the HR 10 
is bigger than the SX 140 by about 3 inches in depth.   Those are pretty 
important factors that can not easily be changed.  I have made up my 
mind....  Off to find one now.

Thanks again

Steve
NU0P


On 6/28/2012 9:21 PM, Walt Hutchens wrote:
> Steve said:
>
>> I am looking at acquiring a HR10B for purposes of making it into my own
>> HRB.  The question that I have relates to whether or not I can use a
>> Hallicrafters SX140 just as well.  They both have approx a 1650 Khz IF
>> and look like either one would work just fine.
> The issues are:
>
> 1. Basically similar concept to the HBRs, for example a ham-band only design
> using a three-gang tuning cap with mechanical reduction, two (or perhaps
> three) IF stages, single conversion with a half lattice or better crystal
> filter ...
>
> 2. Space on the chassis to arrange the three coils in a manner that allows
> adequate shielding and keeps the osc. coil away from heat sources and nearby
> metal or moving parts.
>
> 3. Adequate space for tubes and other parts -- basically plenty of chassis
> area.
>
> 4. An adequate power transformer for the number of tubes you'll use.
>
> 5. A dial of usable quality (reduction ratio, freedom from backlash) that's
> calibrated for the bands you have in mind.   (Since you'll probably want to
> track your new receiver to the existing calibration.)
>
> 6. Suitable structure for a new front panel:  Few commercial receivers will
> have a panel large enough for the type of cabinet you'll want to use for an
> HBR.   The cabinet must be replaced because the usual commercial ham
> receiver doesn't have a top you can open to change coils.   Also most ham
> receiver cabinets and panels from the miniature tube era won't be tall
> enough for the coils.
>
> I've done the HR-10 to HBR reconstruction job so I know that one works.
> While most of the requirements above are subject to some adjustment the big
> advantage of the HR-10 is that VERY little of that is needed.  It is darn
> near a perfect kit of major parts for an HBR, except for coils and front
> panel.   Once you start saying, well ... I COULD use a different dial
> mechanism (pick your part), the trouble goes up fast.
>
> An added advantage of the HR-10:  It started life as a kit so the mechanics
> and space on the chassis are appropriate for a home constructor.   (For
> example, no tight corners, no riveted parts.)  Factory gear is often less
> builder-friendly.
>
> The SX-140, I don't know about so that ground is waiting to be broken by
> some HBR List adventurer!
>
> Walt Hutchens
> KJ4KV
>
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