[AMRadio] Need an HRO "E" coil

JAMES HANLON knjhanlon at msn.com
Mon Aug 14 12:23:09 EDT 2017


Yes, an E coil from any HRO will work.  All HROs are single conversion on this range, so a coil from any of them will work in any other, with certain precautions ...

The coils for the HRO-5 and earlier receivers have two handles, one on each side, that will not fit under the "crowbars" used to put coils in and out in the HRO-7, 50, 50T1 and 60 receivers.  To use one of these earlier coils you will have to cut off the handles to the point where they protrude the same length as the studs found on the later coils.

The coils for the HRO-7 and earlier receivers have the actual coil assemblies mounted higher in the coil shield cans than the coils for the HRO-50 and later.  To use them in a later receiver, you should remove the coil assemblies from their cans and put a washer (spacer) in between the top of the coil assembly and the inside surface of the coil shield can in the three places where the assemblies are held to the cans by screws.  This lowers the assemblies so that they don't damage the mating buss bars in the receiver.

I've used an AC coil from an HRO-7 in my HRO-50 ever since about 1952, and I recently equipped a hamfest find HRO-50R1 with a full set of A, B, C, and D coils from an HRO Senior this way.  The earlier coils align just as they should and work well.

Jim Hanlon, W8KGI

From: Neil Foster <archernf at earthlink.net>
Sent: Friday, August 11, 2017 7:32 AM
To: AMRadio at mailman.qth.net
Subject: [AMRadio] Need an HRO "E" coil

    Still trying....I hope someone can help

           I am helping a friend look for an "E" coil
  for a National 50/60.
          However I understand from the National HRO gurus
  that an earlier
          one will fit with shimming.
           I am not a National guy but a Hammarlund one.
           Any assistance is appreciated.
            Neil   N4FN


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