[ARC5] [Milsurplus] A Cable Question -- MORE

[Mike Hanz]

Reaming is certainly a possibility if you happen to have a set of 
reamers on the tool shelf.  You may be surprised at the cost of a single 
reamer - $30 is about average.  Reamers are normally used for finishing 
holes to extremely exact tolerances, certainly not the requirement 
here.  The coax varies by several thousandths, so you would want the 
diameter of the hole to be a couple of thou above the .405 nominal for 
RG-8.  The easiest way is to chuck the connector in a lathe and simply 
bore it - about 5 minutes max.   Drilling is possible, but you will have 
to have a very rigid setup with no free play in the feed to avoid a two 
flute drill catching in the brass and damaging the thin wall material.  
For only .025" removal, you could also grind it out with a Dremel using 
a continuous circular motion, but the brass will fill the pores in the 
grinding wheel *very* quickly and have to be cleaned off several times 
in the process.  Wish I had known - I coulda bored it out for you before 
I mailed the connector.  I didn't even think about the cable at the 
time...:'(

73,
Mike

On 7/28/2011 9:36 AM, J. Forster wrote:
> AHA!!
>
> That is the answer, IMO.
>
> 13/32" is 0.406"
>
> So Amphenol intended the connector body to be reamed out a bit!
>
> Thanks very much.
>
> Best,
>
> -John
>
> ==================
>
>
>> John, et-al,
>>
>> Checking the Amphenol advert in my 1943 Radio's master again, the
>> description of the type 93 cable end connector says  "....for any co-
>> axial cable up to 13/32" in dia." BUT, then goes on to say "May be
>> reamed out to fit cables up to 9/16"."  I.e., cables up to  0.5265 "
>> so the use of RG-8 (0.405") here may be riginally authentic!
>>
>> Dennis
>>
>> ************
>>
>> On Jul 27, 2011, at 8:49 PM, J. Forster wrote:
>>
>>> Hi Jim,
>>>
>>> The cable goes into the connector shell from the drawings I have. I'm
>>> beginning to think the connector hole is undersized or the cable OD
>>> changed when WW II started.
>>>
>>> Best,
>>>
>>> -John
>>>
>>> =============
>>>
>>>
>>>> John
>>>> I just checked TM11-487 dated 2 October 1944 for information on WW2
>>>> coax.
>>>> On
>>>> page 492 is the data on RG-8 which is still listed as 0.405 inch O.D.
>>>>
>>>> Looking further, for the CASSF-50-1 you mentioned I found that it
>>>> indeed
>>>> cross
>>>> references to RG-8/U and is called out in the column headed as
>>>> "Replaces
>>>> Old
>>>> Cable Number".  Other numbers listed as replaced by RG-8/U are:  PT5,
>>>> WC543,
>>>> WC549.
>>>>
>>>> So I would assume that the jacket is butted up to connector but
>>>> does not
>>>> connect
>>>> to it as is with modern constant impedance connectors.
>>>> Regards,
>>>> Jim
>>>>
>>>>
>>>> ----- Original Message ----
>>>> From: J. Forster<jfor at quikus.com>
>>>> To: arc5 at mailman.qth.net; milsurplus at mailman.qth.net;
>>>> Vintage-Military-RADAR at yahoogroups.com
>>>> Sent: Wed, July 27, 2011 6:54:24 PM
>>>> Subject: [Milsurplus] A Cable Question
>>>>
>>>> OK, this is involved:t.
>>>>
>>>> I'm working on a LORAN-A receiver for a Museum Ship and the antenna
>>>> connector is an Amphenol Type 93. This is an early WW II aardvaark,
>>>> used
>>>> in only a few places AFAIK. Thanks to a generous list member, I now
>>>> have
>>>> the proper connector in hand.
>>>>
>>>> However, the connector will not take standard RG-8 or RG-214 cable.
>>>> Their
>>>> OD is to big.
>>>>
>>>> Assembly instructions from another list member calls out Navy Type
>>>> CASSF-50-1 cable.
>>>>
>>>> Furthermore Google finds in "(1954) AN 16-30ARC5-2 Handbook
>>>> Maintenance
>>>> Instructions AN/ARC-5" that this cable is used to connect a VHF
>>>> ARC-5 to
>>>> the antanna and crosses it to RG-8/U.
>>>>
>>>> However, a check of current catalog of this cable specifies an OD
>>>> of 0.405
>>>> nominal, which will not fit.
>>>>
>>>> Apparently, the OD of RG-8 has changed over time. I think cable of OD
>>>> <0.380" will work. The center conductor needs to be stranded.
>>>>
>>>> So, does anybody know where I can get a few (6?) feet of the stuff,
>>>> even
>>>> more preferably with an PL-259 on one end? I'd buy a roll of maybe
>>>> 100' if
>>>> there is a source.
>>>>
>>>> Thanks,
>>>>
>>>> -John
>>>>
>>>> ================
>>>>
>
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