[ARC5] Missing meter in Phantom Antenna A-61-A (#7777)

[Michael Hanz]

On 4/9/2016 9:27 AM, J Mcvey wrote:
> Everyone has their own objective on how they want to set these up.

This is undeniably true, and thank goodness we have the flexibility to 
exercise it and to receive such great help from people on this list.

> It seems to me that you are making this more difficult than it needs 
> to be, if you just want to have a dummy load test jig.

You might be interested in taking a tour of Ray's excellent restoration 
website at http://www.tuberadio.com/robinson/museum/ It's a good way to 
better understand where he is usually coming from.  As an example, take 
a look at his outstanding article on the ARB.  While we certainly 
understand that some folks enjoy whipping up quick substitutes - and 
most of us here believe there is significant value in that branch of the 
hobby - not everyone wants to bodge things simply to get them working.  
(I have recently become fond of that distinctly British word of 
late...it being a practice in which I have quite a bit of experience.  
It ranks with that wonderful word /swarf/, from /swerf/, also of Old 
English origin, describing the endless piles of machining scrap peeling 
off of the lathe and other machining operations...)

> Why not attach a dummy load to the BC-442 antenna relay which already 
> has the thermocouple and ammeter?
> I made one that fit in a small aluminum box with a variable series cap 
> which I marked optimal positions for 40 and 80 meters. Two leads from 
> the binding posts connect to the BC-442 and the system can be verified 
> in its native state.

Sounds like a great idea!  ...for a bodge... It has the potential added 
benefit of allowing some degree of calibration of the anonymous 10 
division antenna current meter in situ if you have an accurate standard 
to compare it with.

> If you are looking to have an original testbed, then I guess the hunt 
> is on for all of the obscure parts and pieces. Good luck!

Indeed!  Sometimes the chase for the obscure part is half the fun. Some 
of my longest searches for something on my wish list have been satisfied 
by someone from down under.  It goes both ways.

73,
Mike  KC4TOS

> On Saturday, April 9, 2016 8:00 AM, Michael Hanz 
> <aaf-radio-1 at aafradio.org> wrote:
>
>
> On 4/9/2016 3:37 AM, robinson at tuberadio.com 
> <mailto:robinson at tuberadio.com> wrote:
>> Thank you for the information.
>> What type of capacitor is inside?
>> It is a vacuum capacitor?
>
> Yes.  It is the same diameter as the one in the BC-442 antenna relay, 
> but longer, as one would expect.
>
>> My meter is what Mike said,
>> 0-4 (non linear scale) internal thermocouple
>> has a white scale labeled AMPERES R.F.
>> WESTON 507 (metal case) ARC #7781
>>
>> Whereas the ANTENNA RELAY UNIT type BC-442-AM or RE-2/ARC-5
>> 0-10 (linear scale) external thermocouple
>> has a black scale labeled ANTENNA CURRENT INDICATOR
>
> Yup.  The _external_ thermocouple was required in the ATA antenna 
> relay, in the _early_ BC-442 (for a time), and finally in the 
> RE-2/ARC-5, for a very specific purpose.  If you look closely at the 
> test setup in the _first_ diagram at 
> http://aafradio.org/docs/ARC_Test_sets.html , which is from a 1941 
> version of the SCR-274N manual, you will notice a curious meter 
> labeled I-71-B, which is a remote RF ammeter that could be selected by 
> a switch on the antenna relay.  You might be interested in reading 
> "the rest of the story" at http://aafradio.org/flightdeck/I-71A.html
>

-------------- next part --------------
An HTML attachment was scrubbed...
URL: <http://mailman.qth.net/pipermail/arc5/attachments/20160409/33879d77/attachment.html>
-------------- next part --------------
A non-text attachment was scrubbed...
Name: 12.gif
Type: image/gif
Size: 1289 bytes
Desc: not available
URL: <http://mailman.qth.net/pipermail/arc5/attachments/20160409/33879d77/attachment.gif>