[R-390] Baluns Caps and Ballasts

[Dennis Wade]

Bob, what I wrote has nothing to do with the product mentioned above,
and has *everything* to do with how such a device, bought or
homebrewed, is used.  Someone's Ebay feedback is irrelevant here.

The other thing that's irrelevant is what may or may not have been
included in a 60 year old test setup for these receivers.

My post stands, and if anyone else has anything to add, please do.
I'd love to hear from others.

             Dennis

I wrote:

Isn't the whole point of the balun to convert the *unbalanced* 50 ohms
to the *balanced* 125??

Doesn't that solve the problem, assuming one feeds the antenna
properly, that is if feeding a balanced antenna (dipole) with coax
using some sort of choke or other type of balun to keep symmetry.

             Dennis



On Wed, Jul 20, 2011 at 5:05 PM, rbethman <rbethman at comcast.net> wrote:
> I mistakenly screwed up the reply and only sent it directly back to Dennis.
>
> That was NOT my intent!
>
> Seeing that this Individual only has 115 (Approximately) feedback, and
> NO ONE on the list has one, HOW much weight do YOU give to this balun?
>
> Everyone seems to be dodging the whole thing!  It isn't in hand YET!
>
> I learned a LONG time ago about ASSUME.  We ASSUMED the *BAD LOT* of
> 40mm M-79 ammunition was GOOD - UNTIL it armed in 3 meters and went off
> directly overhead!
>
> Assume if you wish.
>
> The only thing I *DO* know, is that the test equipment supplied for the
> R-390As did NOT include such a device.
>
> BAMA EDEBRIS has the formerly stated pdf.  It is under the Military
> section, and is listed way over on the right simply as URM25 - NOT
> AN/URM-25(X).
>
> I would gather that some folks ASSUME a weapon is UNLOADED!
>
> I won't take one into MY hand unless it is OPENED and CLEARED before it
> is offered for me to look at!
>
> Correspondingly, I perform the SAME before offering a weapon to someone
> to look at!
>
> Bob - N0DGN
>
> On 7/20/2011 7:50 PM, Dennis Wade wrote:
>> Why would you not feed the 50 ohm unbalanced generator through the
>> balun for alignment, assuming you had confidence in the balun?
>>
>>                Dennis
>>
>> On Wed, Jul 20, 2011 at 4:02 PM, rbethman<rbethman at comcast.net>  wrote:
>>> ONLY *IF* you do an alignment with a 120 Ohm signal generator.
>>>
>>> Do you see a 120 Ohm terminator/dummy antenna with the AN/URM-25 series?
>>>
>>> Sure wasn't part of the parts included.  Darn sure isn't in the NAVSHIPS
>>> Manual either.
>>>
>>> NAVSHIPS 0967-187-5010.pdf (A 35MB file.).
>>>
>>> Bob - N0DGN
>>>
>>>
>>>
>>> On 7/20/2011 6:53 PM, Dennis Wade wrote:
>>>> Isn't the whole point of the balun to convert the *unbalanced* 50
>>>> ohms to the *balanced* 125?? Doesn't that solve the problem,
>>>> assuming one feeds the antenna properly, that is if feeding a
>>>> balanced antenna (dipole) with coax using some sort of choke or
>>>> other type of balun to keep symmetry.               Dennis
> ______________________________________________________________
> R-390 mailing list
> Home: http://mailman.qth.net/mailman/listinfo/r-390
> Help: http://mailman.qth.net/mmfaq.htm
> Post: mailto:R-390 at mailman.qth.net
>
> This list hosted by: http://www.qsl.net
> Please help support this email list: http://www.qsl.net/donate.html
>



-- 
"If they trust you, it is an extraordinary privilege, and you simply
can't abuse it."
      - A. Alan Post  1914-2011.  California Legislative Analyst 1949-1977.

-------------------------
Dennis L. Wade
KG6ZI
Carmichael, CA