[R-390] Baluns Caps and Ballasts

[Cecil Acuff]

The fact is if you are using a balanced fed dipole you don't use a balun. In 
addition the military never worried about perfect height, nor perfect 
installation techniques nor the antenna being cut for exactly the frequency 
being used.  They worked in a non-perfect world in most all cases when field 
deployed...and yet still gained the benefits of the balanced design quite 
nicely.

This is just hobby radio we are talking about...no ones life depends on it. 
It's forgiving of a multitude of technical sins and still provides a great 
deal of pleasure.  Since it's a hobby, each one of us are free to get as 
intense or as lax as desired in the persuit of the pleasure it offers.  Some 
will optimize their antenna systems as much as is practical and certainly 
providing a better impedance match between our antenna systems and the radio 
will display a measure of improvement..whether it's done with a slick 
looking German engineered device or a home brewed one stuffed in a medicine 
bottle.  That's part of the pleasure and joy of ownership.

Let each have the freedom to do it their way and lets all learn from it in 
an effort to better apply our thoughts and desires as to how we use our 
little vacuum tubed piece of history...

I'm anxious to hear Tisha's report on how it checks out.

Cecil
----- Original Message ----- 
From: "rbethman" <rbethman at comcast.net>
To: "R-390 HF Receiver List" <r-390 at mailman.qth.net>
Cc: "Cecil Acuff" <chacuff at cableone.net>; "Dennis Wade" 
<sacramento.cyclist at gmail.com>
Sent: Wednesday, July 20, 2011 10:53 PM
Subject: Re: [R-390] Baluns Caps and Ballasts


> Precisely!
>
> Now we have done away with *irrelevant", I.E., * Smoke and Mirrors*!
>
> The dipole must be the proper height above ground, a very good ground, and 
> a *perfect*, (no loss), balun or choke to go from 73 ohms to 50 ohms, have 
> no loss in the 50 to 120 Ohm balun.  Haven't EVEN addressed feed-line 
> losses!
>
> The dipole is also good at ONE, or a VERY small frequency range.
>
> Don't look behind the curtain - OMG! The RADIO is 60 years old!
>
> Bob - N0DGN
>
> On 7/20/2011 10:16 PM, Cecil Acuff wrote:
>> You do the alignment through the Balun.  It does the 50 ohm to 120 ohm 
>> impedance matching if wound properly.
>>
>> Sure the most ideal situation would be to have twinax all the way to the 
>> feed point on the dipole but that's not how most are equipped these 
>> days...
>>
>> Unless you build it yourself you will have a 50 or 75 ohm unbalanced 
>> antenna system.  There is a bit to be gained by using the Balun but not 
>> as much as using a balanced antenna system.
>>
>> Cecil..
>> ----- Original Message ----- From: "rbethman" <rbethman at comcast.net>
>> To: "R-390 HF Receiver List" <r-390 at mailman.qth.net>
>> Sent: Wednesday, July 20, 2011 6:02 PM
>> Subject: Re: [R-390] Baluns Caps and Ballasts
>>
>>
>> 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
>>