[TowerTalk] TowerTalk Digest, Vol 269, Issue 7

Tue May 20 07:59:15 EDT 2025

And you would be incorrect.

It had large matching tubes along the boom, with a hairpin stub ground 
in the middle. The large tubes are about 2-3 feet long.

Please look at the manual

Jim W7RY

On 5/19/2025 11:25 PM, Al N6TA wrote:
> The TH6DXX had no such matching, at least on the one I had new and used for
> 20 years.  Coax to BN86 and then directly to the insulated DE,  Simple and
> worked with no adjustments needed or possible.
> Al  N6TA
>
> On Mon, May 19, 2025 at 9:16 AM <towertalk-request at contesting.com> wrote:
>
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>> Today's Topics:
>>
>>     1. Re: HELP - Hy-Gain TH-3JRS (Bill Cotter)
>>     2. Re: HELP - Hy-Gain TH-3JRS (Tom Hellem)
>>     3. Re: HELP - Hy-Gain TH-3JRS (Tom Hellem)
>>     4. Re: HELP - Hy-Gain TH-3JRS (Gary Mayfield)
>>     5. Re: HELP - Hy-Gain TH-3JRS (Wes)
>>     6. Re: HELP - Hy-Gain TH-3JRS (Charles Tifft)
>>
>>
>>
>> ---------- Forwarded message ----------
>> From: Bill Cotter <n4lg at qx.net>
>> To: Gary Mayfield <gary_mayfield at hotmail.com>
>> Cc: "towertalk at contesting.com" <towertalk at contesting.com>
>> Bcc:
>> Date: Sun, 18 May 2025 12:29:38 -0400
>> Subject: Re: [TowerTalk] HELP - Hy-Gain TH-3JRS
>> Gary,
>>
>> Attached is the manual for the TH-3 MK3 that shows the (grounded)
>> beta-match dimensions, and the coax choke. I think the hairpin may
>> be the problem (inductor vs transmission line). I think I would
>> construct the beta match as designed. It should be easy to make up
>> from available materials. And, thoroughly inspecting the traps for
>> electrical integrity and correct location is a must.
>>
>> 73 es GL Bill N4LG
>>
>>
>> At 09:19 AM 5/18/2025, Gary Mayfield wrote:
>>> Thanks Jim,
>>>
>>>          We did test with the long coax on the ground, and your
>>> point is well taken about the balun vs a choke. We will take a
>>> fine tooth comb to our hairpin recreation. I suspect that may be
>>> a contributing factor.
>>>
>>> 73,
>>> Joe n0sd
>>>
>>> -----Original Message-----
>>> From: TowerTalk <towertalk-bounces at contesting.com> On Behalf Of
>>> Jim Brown
>>> Sent: Saturday, May 17, 2025 11:18 PM
>>> To: towertalk at contesting.com
>>> Subject: Re: [TowerTalk] HELP - Hy-Gain TH-3JRS
>>>
>>> On 5/17/2025 6:04 PM, Gary Mayfield wrote:
>>>> We have also added a balun made from type 31 ferrite material.
>>> Hi Gary,
>>>
>>> Don't know anything about that antenna or have a solution for your
>>> problem, BUT -- if that #31 is a lot of turns of transmission line
>>> wound around a 2.4-in o.d. core, it is a Common Mode Choke, NOT a
>>> "balun."
>>> Antennas like yours are designed for specific matching networks or
>>> feeding methods. A choke is used between the transmission line and
>>> that matching system, whatever it is. These matching systems are
>>> often called baluns.
>>>
>>> And with respect to your problem and on-the-ground testing -- did
>>> you have a long length of coax on it when testing on the ground,
>>> or just the analyzer connected with a few feet of coax?  Their
>>> matching networks often want to be driven by that coax.
>>>
>>> Also, study carefully as you can what the original matching system
>>> was.
>>> With gamma and hairpin matching, both the length and the diameter
>>> of the
>>> rod(s) matter.
>>>
>>> 73, Jim K9YC
>>>
>>> _______________________________________________
>>>
>>>
>>>
>>> _______________________________________________
>>> TowerTalk mailing list
>>> TowerTalk at contesting.com
>>> http://lists.contesting.com/mailman/listinfo/towertalk
>>>
>>> _______________________________________________
>>>
>>>
>>>
>>> _______________________________________________
>>> TowerTalk mailing list
>>> TowerTalk at contesting.com
>>> http://lists.contesting.com/mailman/listinfo/towertalk
>>
>>
>>
>> ---------- Forwarded message ----------
>> From: Tom Hellem <tom.hellem at gmail.com>
>> To: "jim.thom jim.thom at telus.net" <jim.thom at telus.net>
>> Cc: towertalk at contesting.com
>> Bcc:
>> Date: Sun, 18 May 2025 12:25:29 -0600
>> Subject: Re: [TowerTalk] HELP - Hy-Gain TH-3JRS
>> The hairpin match , yes a very good question indeed.
>> In fact, so good that Hygain didn’t choose to answer it in
>> their instruction manual. They show all the parts for it, including
>> what looks like an adjustable shorting  bar, but absolutely no
>> mention of it in the text. DX Engineering is still selling them, with
>> the exact same manual. What a joke.
>>
>> Tom K0SN
>>
>> On Sun, May 18, 2025 at 8:35 AM jim.thom jim.thom at telus.net <
>> jim.thom at telus.net> wrote:
>>
>>> Date: Sun, 18 May 2025 13:19:54 +0000
>>> From: Gary Mayfield <gary_mayfield at hotmail.com>
>>> To: "towertalk at contesting.com" <towertalk at contesting.com>
>>> Subject: Re: [TowerTalk] HELP - Hy-Gain TH-3JRS
>>>
>>>
>>>
>>>         > We did test with the long coax on the ground, and your point is
>>> well taken about the >balun vs a choke. We will take a fine tooth comb to
>>> our hairpin recreation. I suspect that >may be a contributing factor.
>>>
>>>> 73,
>>>> Joe n0sd
>>> How exactly does Hygain manage to get a hairpin to work on 3 bands ???
>>> Typ when you raise the yagi from 8'  to top of tower, the resonance
>> points
>>> will  all shift up in freq.
>>>
>>> Jim   VE7RF
>>> _______________________________________________
>>>
>>>
>>>
>>> _______________________________________________
>>> TowerTalk mailing list
>>> TowerTalk at contesting.com
>>> http://lists.contesting.com/mailman/listinfo/towertalk
>>>
>>
>>
>>
>> ---------- Forwarded message ----------
>> From: Tom Hellem <tom.hellem at gmail.com>
>> To: Bill Cotter <n4lg at qx.net>
>> Cc: Gary Mayfield <gary_mayfield at hotmail.com>, "towertalk at contesting.com"
>> <towertalk at contesting.com>
>> Bcc:
>> Date: Sun, 18 May 2025 18:42:26 -0600
>> Subject: Re: [TowerTalk] HELP - Hy-Gain TH-3JRS
>> There is no difference between a hairpin match and a beta match, its just 2
>> different names for the same thing.
>> My understanding of them is that it's  a device for raising the feedpoint Z
>> of a yagi, typically 25-35 ohms, up to 50 ohms. But when you build one, you
>> can only adjust its length for one frequency band. I have never seen one
>> used on a tribander, only on monoband antennas.
>>
>> Could this be another example of confusion on the part of the folks at MFJ?
>> Maybe they got tribanders mixed up with monobanders and just stuck a beta
>> match on the TH-3JR-S because they didn't know any better.
>>
>> All of the trapped tribanders that I have worked with, and it's been quite
>> a few, were direct fed with no matching system. The  losses in the traps
>> probably provide the extra Z to arrive at 50 ohms.
>>
>> It might be worth just removing the beta match altogether and see what
>> happens.
>>
>> K0SN
>>
>>
>> On Sun, May 18, 2025 at 10:33 AM Bill Cotter <n4lg at qx.net> wrote:
>>
>>> Gary,
>>>
>>> Attached is the manual for the TH-3 MK3 that shows the (grounded)
>>> beta-match dimensions, and the coax choke. I think the hairpin may
>>> be the problem (inductor vs transmission line). I think I would
>>> construct the beta match as designed. It should be easy to make up
>>> from available materials. And, thoroughly inspecting the traps for
>>> electrical integrity and correct location is a must.
>>>
>>> 73 es GL Bill N4LG
>>>
>>>
>>> At 09:19 AM 5/18/2025, Gary Mayfield wrote:
>>>> Thanks Jim,
>>>>
>>>>          We did test with the long coax on the ground, and your
>>>> point is well taken about the balun vs a choke. We will take a
>>>> fine tooth comb to our hairpin recreation. I suspect that may be
>>>> a contributing factor.
>>>>
>>>> 73,
>>>> Joe n0sd
>>>>
>>>> -----Original Message-----
>>>> From: TowerTalk <towertalk-bounces at contesting.com> On Behalf Of
>>>> Jim Brown
>>>> Sent: Saturday, May 17, 2025 11:18 PM
>>>> To: towertalk at contesting.com
>>>> Subject: Re: [TowerTalk] HELP - Hy-Gain TH-3JRS
>>>>
>>>> On 5/17/2025 6:04 PM, Gary Mayfield wrote:
>>>>> We have also added a balun made from type 31 ferrite material.
>>>> Hi Gary,
>>>>
>>>> Don't know anything about that antenna or have a solution for your
>>>> problem, BUT -- if that #31 is a lot of turns of transmission line
>>>> wound around a 2.4-in o.d. core, it is a Common Mode Choke, NOT a
>>>> "balun."
>>>> Antennas like yours are designed for specific matching networks or
>>>> feeding methods. A choke is used between the transmission line and
>>>> that matching system, whatever it is. These matching systems are
>>>> often called baluns.
>>>>
>>>> And with respect to your problem and on-the-ground testing -- did
>>>> you have a long length of coax on it when testing on the ground,
>>>> or just the analyzer connected with a few feet of coax?  Their
>>>> matching networks often want to be driven by that coax.
>>>>
>>>> Also, study carefully as you can what the original matching system
>>>> was.
>>>> With gamma and hairpin matching, both the length and the diameter
>>>> of the
>>>> rod(s) matter.
>>>>
>>>> 73, Jim K9YC
>>>>
>>>> _______________________________________________
>>>>
>>>>
>>>>
>>>> _______________________________________________
>>>> TowerTalk mailing list
>>>> TowerTalk at contesting.com
>>>> http://lists.contesting.com/mailman/listinfo/towertalk
>>>>
>>>> _______________________________________________
>>>>
>>>>
>>>>
>>>> _______________________________________________
>>>> TowerTalk mailing list
>>>> TowerTalk at contesting.com
>>>> http://lists.contesting.com/mailman/listinfo/towertalk
>>> _______________________________________________
>>>
>>>
>>>
>>> _______________________________________________
>>> TowerTalk mailing list
>>> TowerTalk at contesting.com
>>> http://lists.contesting.com/mailman/listinfo/towertalk
>>>
>>
>>
>>
>> ---------- Forwarded message ----------
>> From: Gary Mayfield <gary_mayfield at hotmail.com>
>> To: "'towertalk at contesting.com'" <towertalk at contesting.com>
>> Cc:
>> Bcc:
>> Date: Mon, 19 May 2025 00:46:43 +0000
>> Subject: Re: [TowerTalk] HELP - Hy-Gain TH-3JRS
>> We had a much better day today. We removed the hairpin, and the choke and
>> fed the antenna with split coax and got the same results as before. --- Has
>> to be a trap...
>>
>> The traps all measure as dead shorts at DC (expected), but while measuring
>> one of the traps with an ohmmeter a sweep of the antenna shows dips (off
>> frequency) in the SWR (not just flat bad).
>>
>> We took that trap apart and it looked great, but we did get two tiny drops
>> of dirty water. It was damp, but not wet. We cleaned it and put it back
>> together and presto - three nice dips, pretty much on frequency.
>>
>> We reconnected the hairpin and the in band SWR went from around 3 to 1 in
>> each band to around 1.2 to 1 on each band (hey it really does help match
>> the antenna).  We added the choke and it didn't have any SWR impact, but we
>> are quite pleased and Rich's new antenna is on the air. The lift can be
>> returned in the morning. If you hear Rich ke0epy (originally wn0vzp) on the
>> air - say howdy!
>>
>> Thanks to all the folks who provided input. This reflector is a great
>> sounding board!
>>
>> 73,
>> Joe n0sd
>>
>> -----Original Message-----
>> From: TowerTalk <towertalk-bounces at contesting.com> On Behalf Of Gary
>> Mayfield
>> Sent: Saturday, May 17, 2025 8:04 PM
>> To: 'towertalk at contesting.com' <towertalk at contesting.com>
>> Subject: [TowerTalk] HELP - Hy-Gain TH-3JRS
>>
>> Hello - We had a frustrating afternoon today trying to put up a Hy-Gain
>> TH-3JRS at the QTH of Rich, KE0EPY.
>>
>> The antenna is previously owned, and we replaced the broken aluminum
>> matching wire (beta match) with one made of copper. We have also added a
>> balun made from type 31 ferrite material. Other than that, the antenna
>> seems to be all original. A few days ago, we tested the antenna on top of
>> an 8-foot fiberglass ladder, and it had three nice SWR dips right where you
>> would expect for 20, 15 and 10 meters. Today before taking the antenna up
>> the tower, we checked it all again, by pointing it lifting it a couple feet
>> and pointing it straight up. Again, we saw 3 nice dips where they were
>> expected.
>>
>> Once we mounted it on the tower the SWR went very high and only showed one
>> small dip just below 15 meters at 20.8 MHz. Thinking the coax had been
>> damaged we took a small jumper up in the lift and connected directly to the
>> balun but got the same results. Then we bypassed the balun - same results.
>> We removed the beta match and connected straight to the driven element and
>> got the same results. With the beta match removed the two sides of the
>> driven element are not shorted to each other or the boom.
>>
>> We have the lift for another day. Any ideas/thought/suggestions will be
>> greatly appreciated!!
>>
>> Thanks, and 73,
>> Joe - n0sd
>> _______________________________________________
>>
>>
>>
>> _______________________________________________
>> TowerTalk mailing list
>> TowerTalk at contesting.com
>> http://lists.contesting.com/mailman/listinfo/towertalk
>>
>>
>>
>>
>>
>> ---------- Forwarded message ----------
>> From: Wes <wes_n7ws at triconet.org>
>> To: towertalk at contesting.com
>> Cc:
>> Bcc:
>> Date: Mon, 19 May 2025 06:21:13 -0700
>> Subject: Re: [TowerTalk] HELP - Hy-Gain TH-3JRS
>> The beta or hairpin match is an L-network with a shortened driven element
>> providing the capacitance and the hairpin providing the inductance.  It is
>> not
>> necessarily a single-band solution.
>>
>> IIRC, the TH-3, TH-3JR and the TH6DXX all used them.
>>
>> Wes  N7WS
>>
>>
>> On 5/18/2025 5:42 PM, Tom Hellem wrote:
>>> There is no difference between a hairpin match and a beta match, its
>> just 2
>>> different names for the same thing.
>>> My understanding of them is that it's  a device for raising the
>> feedpoint Z
>>> of a yagi, typically 25-35 ohms, up to 50 ohms. But when you build one,
>> you
>>> can only adjust its length for one frequency band. I have never seen one
>>> used on a tribander, only on monoband antennas.
>>>
>>> Could this be another example of confusion on the part of the folks at
>> MFJ?
>>> Maybe they got tribanders mixed up with monobanders and just stuck a beta
>>> match on the TH-3JR-S because they didn't know any better.
>>>
>>> All of the trapped tribanders that I have worked with, and it's been
>> quite
>>> a few, were direct fed with no matching system. The  losses in the traps
>>> probably provide the extra Z to arrive at 50 ohms.
>>>
>>> It might be worth just removing the beta match altogether and see what
>>> happens.
>>>
>>> K0SN
>>>
>>
>>
>> ---------- Forwarded message ----------
>> From: Charles Tifft <chuckw6rd at yahoo.com>
>> To: Wes <wes_n7ws at triconet.org>
>> Cc: towertalk at contesting.com
>> Bcc:
>> Date: Mon, 19 May 2025 06:29:37 -0700
>> Subject: Re: [TowerTalk] HELP - Hy-Gain TH-3JRS
>> Couple Wilson Tribanders too. SYS1 and SYS36  come to mind.
>> W6RD
>>
>>> On May 19, 2025, at 6:21 AM, Wes <wes_n7ws at triconet.org> wrote:
>>>
>>> The beta or hairpin match is an L-network with a shortened driven
>> element providing the capacitance and the hairpin providing the
>> inductance.  It is not necessarily a single-band solution.
>>> IIRC, the TH-3, TH-3JR and the TH6DXX all used them.
>>>
>>> Wes  N7WS
>>>
>>>
>>> On 5/18/2025 5:42 PM, Tom Hellem wrote:
>>>> There is no difference between a hairpin match and a beta match, its
>> just 2
>>>> different names for the same thing.
>>>> My understanding of them is that it's  a device for raising the
>> feedpoint Z
>>>> of a yagi, typically 25-35 ohms, up to 50 ohms. But when you build one,
>> you
>>>> can only adjust its length for one frequency band. I have never seen one
>>>> used on a tribander, only on monoband antennas.
>>>>
>>>> Could this be another example of confusion on the part of the folks at
>> MFJ?
>>>> Maybe they got tribanders mixed up with monobanders and just stuck a
>> beta
>>>> match on the TH-3JR-S because they didn't know any better.
>>>>
>>>> All of the trapped tribanders that I have worked with, and it's been
>> quite
>>>> a few, were direct fed with no matching system. The  losses in the traps
>>>> probably provide the extra Z to arrive at 50 ohms.
>>>>
>>>> It might be worth just removing the beta match altogether and see what
>>>> happens.
>>>>
>>>> K0SN
>>>>
>>> _______________________________________________
>>>
>>>
>>>
>>> _______________________________________________
>>> TowerTalk mailing list
>>> TowerTalk at contesting.com
>>> http://lists.contesting.com/mailman/listinfo/towertalk
>>
>>
>> _______________________________________________
>> TowerTalk mailing list
>> TowerTalk at contesting.com
>> http://lists.contesting.com/mailman/listinfo/towertalk
>>
> _______________________________________________
>
>
>
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