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Less Than Perfect Antennas [was Flumoxed]

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Bob McGraw - K4TAX

Less Than Perfect Antennas [was Flumoxed]

I'm the one that made the recommendations.    Other than the two Balun
Designs units and the #8232 units from The Wireman being used with my
station..............I don't know a darn thing about them other
than...........they work.   I'm not using a 1115T balun. Measuring the
baluns and putting results on paper is one thing. Putting them into a
station configuration and using them, as I have, is another.    I
prefer the latter.

73

Bob, K4TAX

On 12/9/2018 12:47 PM, Jim Brown wrote:

> I wonder if anyone using or recommending products like this have ever
> measured them. They are not easy to measure. You can't measure them
> accurately with a single-port antenna analyzer.
>
> N6KT, a member of our contest club is building a station in the
> Caribbean and asked me to measure a Balun Designs 1115T common mode
> choke (often called a 1:1 current balun). It looks NOTHING like it's
> data sheet, which shows an approximately flat high choking impedance
> over the HF bands. It would be USELESS on 40, 80, and 160M! From what
> I've seen them write about chokes, I don't believe that they
> understand how common mode chokes work, and I certainly wouldn't
> suggest that someone ask them for advice.
>
> The Wireman 8232 is based on W2DU's excellent work from many years
> ago. He built chokes with 50, 100, and 200 of the largest #73
> Fair-Rite beads that fit over RG142. This size bead of this material
> has the unique property of relatively constant choking impedance in
> the HF spectrum, but you have to a LOT of them. Only the 200-bead
> choke has sufficient choking impedance to handle high power and kill
> receive noise, and that's what he recommended, yet most products sold
> as a "W2DU balun" have many fewer. The larger #31 cores are not useful
> at HF until you wind multiple turns through them, but are often sold
> for use as a string of beads on coax.
>
> How many beads are in the 8232? Are they Fair-Rite #73?
>
> 73, Jim K9YC
>
> On 12/9/2018 5:33 AM, Bob McGraw K4TAX wrote:
>> Balun Designs, both 1:1 and 4:1 for use with tuners. I have both
>> because I also have a folded dipole that I feed direct.
>>
>> I suggest you give the folks at Balun Designs a call and discuss your
>> exact needs. Take their advice.
>> Also see the DJ0IP site for details on baluns. Just Google DJ0IP.
>>
>> And I use the 8232 common mode choke from The Wireman.

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Jim Brown-10

Re: Less Than Perfect Antennas [was Flumoxed]

On 12/9/2018 5:15 PM, Bob McGraw K4TAX wrote:
> I don't know a darn thing about them other
> than...........they work.

Define "they work." :) They don't blow up? You get signal through them
to the antenna? They reduce common mode current? They reduce RX noise?
You make QSOs with them in line? They make you feel good?

The REASON for using a common mode choke is to reduce common mode
current. That can reduce noise a bit -- the part of it picked up on the
feedline, and it can eliminate the part of TX RF coming into the shack
on the feedline as common mode current. By my definition, if a choke
does that, or can do that if there's noise, it works. If it doesn't do
that, or can't d that, it's not working or it's not a good choke.

Chokes installed on antennas rarely make a large difference in noise --
a few dB is typical if your antenna is close to the noise source, it
also picks up the noise. But if the antenna is far from the noise source
and the feedline runs close to the source, the reduction can be more
than a few dB. AND, when that DX you're trying to work is weak, that few
dB can be the difference between copying him or not!

73, Jim K9YC

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David Gilbert

Re: Less Than Perfect Antennas [was Flumoxed]

In reply to this post by Bob McGraw - K4TAX

It doesn't sound like you have a clue how WELL they work, though,
relative to not using one at all or using one that has verified specs.
Lots of stuff "works" but doesn't work as well as it should.
Personally, I don't see the merit in preferring not to know, and it's a
good thing for the rest of us that there are hams out there who have
over the last hundred years tried to put science into our hobby.

Dave AB7E

On 12/9/2018 6:15 PM, Bob McGraw K4TAX wrote:

> I'm the one that made the recommendations.    Other than the two Balun
> Designs units and the #8232 units from The Wireman being used with my
> station..............I don't know a darn thing about them other
> than...........they work.   I'm not using a 1115T balun. Measuring the
> baluns and putting results on paper is one thing. Putting them into a
> station configuration and using them, as I have, is another.    I
> prefer the latter.
>
> 73
>
> Bob, K4TAX
>

Bob McGraw - K4TAX

My recent and general posting

In reply to this post by Jim Brown-10

I did not suggest a particular type balun as I do not know the specifics
of the antenna system being used.   Thus based my recommendation to
contact the company for a discussion with them.    I feel they are
better qualified than any of us in this regard.   As to measuring one
balun model and slamming the entire product line is certainly not the
best demonstration of ones understanding the subject.

All of the comments allegedly slamming me or berating me for my
statements of general nature are done without knowledge of what exactly
I have, how I use the items and the measurements I've made.   These are
real world results and not lab measurements or computer generated results.

To each his own and I'll stand by mine and the likewise results.

73
Bob, K4TAX

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Bob McGraw - K4TAX

Re: Less Than Perfect Antennas [was Flumoxed]

In reply to this post by Bob McGraw - K4TAX

Before Eric steps in, let me say "let's end this discussion. It has
veered too far from the original posting".

73

Bob, K4TAX

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k6dgw

Re: Less Than Perfect Antennas [was Flumoxed]

Yes, and to think I so deftly avoided using that "b" word that ends in
"n" in the original post. The original post was just an observation
that antennas do not need to be perfect to work ... and sometimes work
well. I'm beginning to think that any post on any ham radio subject
will eventually devolve into repetitive discussions about that dreaded
"b" thing, the "c" thing, or both.

73,
Fred ["Skip"] K6DGW
Sparks NV DM09dn
Washoe County

On 12/10/2018 7:20 AM, Bob McGraw K4TAX wrote:
> Before Eric steps in, let me say "let's end this discussion. It has
> veered too far from the original posting".
>
> 73
>
> Bob, K4TAX

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Ron Genovesi

Re: Less Than Perfect Antennas [was Flumoxed]

In reply to this post by Bob McGraw - K4TAX

Veered oh yes.
Worse than that, it been literally beat to death! Many times over.and over and over

Ron Genovesi
N3ETA
Sent from my iPhone

> On Dec 10, 2018, at 7:20 AM, Bob McGraw K4TAX <[hidden email]> wrote:
>
> Before Eric steps in, let me say "let's end this discussion. It has veered too far from the original posting".
>
> 73
>
> Bob, K4TAX
>
>
>
>
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Eric Swartz - WA6HHQ

Re: Less Than Perfect Antennas [was Flumoxed]

Administrator

Thread closed so we don't thrash it any more..

73,
Eric
Mooderator
/elecraft.com/

On 12/10/2018 1:32 PM, Ron Genovesi wrote:

> Veered oh yes.
> Worse than that, it been literally beat to death! Many times over.and over and over
>
> Ron Genovesi
> N3ETA
> Sent from my iPhone
>
>> On Dec 10, 2018, at 7:20 AM, Bob McGraw K4TAX <[hidden email]> wrote:
>>
>> Before Eric steps in, let me say "let's end this discussion. It has veered too far from the original posting".
>>
>> 73
>>
>> Bob, K4TAX