Of course, my Siamese cat-tenna will only operate in the “Morris Code” portion
of the bands.
LOL
Gary
> On Jul 18, 2016, at 9:14 AM, rick@dj0ip.de <Rick@dj0ip.de> wrote:
>
> Hi Gary,
>
> I found time to come back in and continue addressing more of the points.
>
> Nothing is wrong with the resonant antenna. It is what I have used quite a
> lot over the years.
> We are on the same page here. However it is wrong to believe that only
> resonant antennas can be efficient. Maxwell clearly points that out, as does
> Cevik.
>
> I was only saying that people often are forced to use non-resonant antennas
> due to space limitations and that the JVM (in standard format) is not the
> best matchbox for that.
>
> I was in full concert with you on all points, except ... and maybe it wasn’t
> even you who said it . . . it was claimed several times that the JVM was the
> greatest matchbox ever. It was great in its days, but had weaknesses later
> as we got more bands and people began to match funny things with them. At
> least one company (Annecke) improved on the design and sold them. It was
> distinctively better.
>
> But wait, W6SAI published an article showing how to do that, something like
> 50 years ago. That's where I "borrowed" the idea, then applied it to the JVM
> and improved it and published instructions on how to d-i-y.
>
> I went to great length to explain and show people how to remedy this and many
> people have applied my mod to their JVM. I continue to get thank you emails
> for the work from people who have successfully done the mod.
>
> I am a firm believer in link coupler matchboxes and have a couple of pages on
> my web showing people how to build their own simple, dirt cheap link coupled
> matchbox. But I have altogether 4 different circuits for 4 different
> applications.
> Each fits a different set of circumstances where it works, but it fails
> everywhere else. It is difficult to put them all in one box and the high
> power switch would cost a small fortune. So I make different proposals for
> people confronted with different tough environmental situations . . . such
> as how to get a relatively efficient power transfer into a short 20m (66 ft.)
> long (or even shorter) dipole on 160m.
>
> I love quads and loops much more than dipoles.
> I began feeding them with open wire back in the 1970s, using the Annecke
> Symmetrical Coupler, which was the matchbox that is an improvement over the
> JVM. Except mine was home-brew using spare parts I purchased directly from
> Annecke.
>
> HOWEVER THE FACT REMAINS: THERE AREN'T ENOUGH JVM's to go around if everyone
> wants one.
> Even if you are lucky enough to find one, you often find them "melted" on the
> inside.
> Therefore some kind of alternative is required.
>
> A much less quality but very practical solution is to use a good 1:1 Guanella
> balun between a simple L-Network and the openwire. That's "1:1, not "4:1".
> I often use the Model 238 like this.
> Especially with low power (100w or less), this can be a good substitute.
>
> In my 45 years of living on this side of the pond, I have never once seen a
> JVM for sale on the used market. The ANNECKE I speak of was great, but
> Alfred Annecke built and sold exactly 20 units. I built my own. So there
> are perhaps 21 units floating around somewhere in the world. Won't find one
> of those either. So most people must seek or build something else.
>
> Now to your two cats and the JVM.
> I built something similar using two galvanized trash cans.
> You can find a picture here:
> http://www.dj0ip.de/antennas/
> Pictured is one version which I fed with a short coax.
>
> I'll put that up against your Siamese cats any day! (hi)
>
> Cheers Gary!
>
> 73
> Rick, DJ0IP
>
>
> -----Original Message-----
> From: TenTec [mailto:tentec-bounces@contesting.com] On Behalf Of Gary J
> FollettDukes HiFi
> Sent: Monday, July 18, 2016 9:42 AM
> To: Discussion of Ten-Tec Equipment
> Subject: Re: [TenTec] OT: Question to the group
>
>
>
>>> Stating individual cases where something worked proves nothing.
>
> Well, actually it does. As I pointed out, with a RESONANT cubical quad,
> driven with 470 Ohm Dentron parallel line, I got a perfect match on 20, 15
> and 10. This was an efficient antenna with efficient feed lines and an
> efficient (in this application) tuner. It was positioned quite a long
> distance from the transmitter so the lower loss parallel feeling was of some
> advantage.
>
> Better would have been the use low loss ceramic spacers and true parallel
> ladder line. However, the Johnson matchbox would have worked equally well in
> that application, whereas the autotuners and most of the T match tuners
> wouldn’t have worked at all without an external BALUN.
>
> Since my radio at the time, a Drake TR7, had pretty good low pass filters
> within, I was not too concerned that the Matchbox offered no such lowpass
> filtering.
>
> Even more important than the match is the near-perfect balance of currents on
> the line (as you mentioned). Two bad things happen when the currents on
> “parallel” lines are not balanced. Your noise level on receive goes up since
> the feedline begins to act as part of the antenna and your chances of getting
> the Worked All Neighbors award in transmit also goes up dramatically as the
> feed line begins to radiate where you do not want it to radiate.
>
> Nothing matches everything. Nothing even works well for everything. Devices
> like this need to be matched to the application. I only sang the praises of
> the Johnson because it did indeed work with every application in which I used
> it.
>
> Nothing else did as well…
>
> As I said before, improvement is always welcome and what you discuss in terms
> of such improvements is great. Why does this become contentious?
>
> A little humor, if that’s allowed:
>
> I once got a perfect match with a Johnson Matchbox using two cats as an
> antenna, with alternately polarized mice as spacers for feed line made of old
> violin strings (catgut).
>
> Of course, they were Siamese cats… It was, after all, a balanced dipole…
>
> April fools...
>
>
> Beyond that, what is wrong with resonant antennas? Where is the advantage of
> a non-resonant antenna? Nikola Tesla clearly showed the inherent advantages
> of resonant loads 120 years ago… They are pretty easy to match too!
>
>
>> On Jul 18, 2016, at 1:09 AM, Gary J FollettDukes HiFi
>> <dukeshifi@comcast.net> wrote:
>>
>> I’ll just stay with resonant antennas…
>>
>> Gary
>>
>>
>>> On Jul 18, 2016, at 12:48 AM, rick@dj0ip.de <Rick@dj0ip.de> wrote:
>>>
>>> Stating individual cases where something worked proves nothing.
>>> I've had half a dozen cases where it did not work and other matchboxes did.
>>>
>>> In order to gain clarity on this, you must try it with all kinds of
>>> antennas; resonant antennas, long antennas, short antennas, odd sized
>>> loops, etc.
>>>
>>> What the Johnson does well is push equal amounts of current into both
>>> wires of the feedline with relatively high efficience, if and only if
>>> it finds a match.
>>> What it does poor is match over a very broad matching range.
>>>
>>> You don't have to trust me; try it as I have and compare it to an
>>> MFJ-974 or MHF-976.
>>>
>>> OR... simply read the ARRL test report where the ARRL shows several
>>> balanced matchboxes and their matching ranges, including the JVM.
>>>
>>> Now I guess I have to go research the issue it was printed in because
>>> it's probably too much work for some of the readers.
>>>> "A New Generation of Balanced Antenna Tuners", by Joel Hallas, W1ZR,
>>>> QST
>>> September 2004.
>>>
>>> OR, simply do what I have said her MANY TIMES, go to my web site,
>>> find the page on MATCHBOX-SHOOTOUT And read the page, plus download
>>> the file at the bottom of the page.
>>> THERE you will find a nice colorful Excel spreadsheet comparing the
>>> matching range of the various matchboxes.
>>> THERE you will see that the JVM was indeed limited in matching range.
>>>
>>> THEN go read my web page on how to fix it.
>>>
>>> AND THEN YOU WILL HAVE THE BEST MATCHBOX EVER! ;-)
>>>
>>> 73
>>> Rick, DJ0IP
>>>
>>>
>>> -----Original Message-----
>>> From: TenTec [mailto:tentec-bounces@contesting.com] On Behalf Of
>>> Carter
>>> Sent: Saturday, July 16, 2016 9:32 PM
>>> To: tentec@contesting.com
>>> Subject: Re: [TenTec] OT: Question to the group
>>>
>>> On 7/16/2016 10:13 AM, Carter wrote:
>>>> On 7/15/2016 6:59 PM, Jim Allen wrote:
>>>>
>>>>> I had one of those [135 foot dipole fed with ladder line], not at
>>>>>> 60', about half that. CC&Rs and all that.
>>>>
>>>> The exact setup I've got, also at 30 feet.
>>>>
>>>>> What is a "well designed truly balanced antenna tuner?" From what
>>>>>> I've read, there aren't many.
>>>>
>>>> Johnson Matchbox, kW or 275 watt version, not "perfection" but
>>>> certainly very good -- and readily available at a fairly modest price.
>>>>
>>>> Just my 2 cents...
>>>>
>>>> Carter K8VT
>>>>
>>>
>>> Sorry, forgot to mention it earlier...
>>>
>>> Not to say my Johnson kW matchbox is the "best ever"; however, it
>>> works flawlessly with my FT1000MP and 135 foot ladder line fed
>>> dipole on ALL (including WARC) bands. Worst case is 2.1:1 on 30
>>> meters, all other bands 1:1.
>>>
>>> Carter K8VT
>>>
>>> ---
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>>>
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