[TowerTalk] Fw: Flag Antenna Transformer

Thu Feb 2 08:41:56 PST 2012

Al - No problem. Easy to do on such a busy thread.
I just like to encourage the use of flags and pennants. They certainly are 
very effective rx antennas. I've made a system using two four direction 
pennant arrays, phased, using transformer matching and 75 ohm feed. It works 
great, definitely better than my tx antenna, but nothing like beverages 
being used by guys within 100 miles of me.
Gene / W2LU

----- Original Message ----- 
From: "Al Kozakiewicz" <akozak at hourglass.com>
To: "Gene Fuller" <w2lu at rochester.rr.com>; <towertalk at contesting.com>
Sent: Thursday, February 02, 2012 10:27 AM
Subject: Re: [TowerTalk] Fw: Flag Antenna Transformer

> I'm sorry, I wasn't implying a mismatch as the culprit.  I was commenting 
> on an earlier remark.
>
> You were just the catalyst!
>
> Al
> AB2ZY
> ________________________________________
> From: towertalk-bounces at contesting.com [towertalk-bounces at contesting.com] 
> On Behalf Of Gene Fuller [w2lu at rochester.rr.com]
> Sent: Thursday, February 02, 2012 10:21 AM
> To: towertalk at contesting.com
> Subject: [TowerTalk] Fw:  Flag Antenna Transformer
>
> ----- Original Message -----
> From: "Gene Fuller" <w2lu at rochester.rr.com>
> To: "Al Kozakiewicz" <akozak at hourglass.com>
> Sent: Thursday, February 02, 2012 10:19 AM
> Subject: Re: [TowerTalk] Flag Antenna Transformer
>
>
>> Al -My guess is that it was just being completely over powered, not due 
>> to
>> a mismatch. Gene / W2LU
>> ----- Original Message -----
>> From: "Al Kozakiewicz" <akozak at hourglass.com>
>> To: "Gene Fuller" <w2lu at rochester.rr.com>; "Pete Smith N4ZR"
>> <n4zr at contesting.com>; <towertalk at contesting.com>
>> Sent: Thursday, February 02, 2012 10:09 AM
>> Subject: RE: [TowerTalk] Flag Antenna Transformer
>>
>>
>> I constructed a K9AY initially using a Minicircuits device for the
>> transformer.  I can state unequivocally that they are very delicate.  My
>> K9AY is 100 feet away from a Butternut vertical.  Tuning the AL-1500 up 
>> on
>> 40m creates enough induced power to reliably blow that transformer every
>> time.
>>
>> Al
>> AB2ZY
>>
>> ________________________________________
>> From: towertalk-bounces at contesting.com [towertalk-bounces at contesting.com]
>> On Behalf Of Gene Fuller [w2lu at rochester.rr.com]
>> Sent: Thursday, February 02, 2012 10:06 AM
>> To: Pete Smith N4ZR; towertalk at contesting.com
>> Subject: Re: [TowerTalk] Flag Antenna Transformer
>>
>> Keep  in mind that on 75/80 meters a pennant, flag, or ewe will only have
>> a
>> "gain" of around -20dbi. so another db or two of loss due to miss match
>> will hardly be noticed and certainly isn't going to result in result in
>> damage due to heat or rf burns - or am I missing something ? However, if
>> you're running a "phased" pair with transformer "matching" you would want
>> to
>> keep track of the phasing.
>> Gene / W2LU
>>
>> ----- Original Message -----
>> From: "Pete Smith N4ZR" <n4zr at contesting.com>
>> To: <towertalk at contesting.com>
>> Sent: Thursday, February 02, 2012 6:30 AM
>> Subject: Re: [TowerTalk] Flag Antenna Transformer
>>
>>
>>> Is this necessarily true?  I have a couple of transformers built by
>>> ON4UN.  They use separate windings and a binocular core, and behave
>>> exactly as expected.
>>>
>>> 73, Pete N4ZR
>>> The World Contest Station Database, updated daily at
>>> www.conteststations.com
>>> The Reverse Beacon Network at http://reversebeacon.net, blog at
>>> reversebeacon.blogspot.com,
>>> spots at telnet.reversebeacon.net, port 7000 and
>>> arcluster.reversebeacon.net, port 7000
>>>
>>>
>>> On 2/1/2012 4:58 PM, Doug Ronald wrote:
>>>> You are getting these results because you wound a conventional
>>>> transformer
>>>> where a Transmission Line Transformer (TLT) is required. The core is
>>>> fine,
>>>> but twist the primary with the secondary using 12 turns and 3 turns.
>>>> Here
>>>> is
>>>> a reference to some theory on what you need:
>>>>
>>>> http://home.earthlink.net/~christrask/TraskTLTTutorial.pdf
>>>>
>>>> and the author (Chris Trask) has several other TLT articles on his web
>>>> site
>>>> including precise winding tips.
>>>>
>>>> Here is another helpful link to the way your finished transformer 
>>>> should
>>>> look:
>>>>
>>>> http://www.qsl.net/wa1ion/bev/bb_antenna_matching.pdf
>>>>
>>>> Hope that helps,
>>>>
>>>> -Doug, AE6SY
>>>>
>>>>
>>>>
>>>>> I have a flag antenna which has worked well for several years. I used 
>>>>> a
>>>> Minicircuits T16-6 transformer to couple the ~800 ohm termination
>>>> resistance
>>>> of the antenna to 50 ohm line. Recently I decided to do some upgrades,
>>>> so
>>>> I
>>>> followed the recommendations of many (here and elsewhere) and made a
>>>> matching transformer using an FT-140-43 core and 34:8 turns, secondary
>>>> and
>>>> primary on opposite sides of the core. I didn't have any #28 wire so I
>>>> used
>>>> #24. I tested this with a miniVNA, terminating the antenna side with an
>>>> 800
>>>> ohm noninductive resistor. The impedance does not look right at all;
>>>> there
>>>> is a lot of inductive reactance and the resistive part starts at 125
>>>> ohms
>>>> and climbs steeply from 1.7 MHz. No on-the-air results yet.
>>>>
>>>>
>>>>
>>>> I'm wondering if this is right or not - measurements indicate the DIY
>>>> transformer is much worse than the T16-6 in terms of presenting a good
>>>> match.
>>>>
>>>>
>>>>
>>>> This would not be the first case of theory saying it won't work but
>>>> practice
>>>> says it will - just looking for a reality check here. Seems to me like
>>>> the
>>>> core material is all wrong...
>>>>
>>>>
>>>>
>>>> -Tony, K1KP
>>>>
>>>>
>>>>
>>>> _______________________________________________
>>>>
>>>>
>>>>
>>>> _______________________________________________
>>>> TowerTalk mailing list
>>>> TowerTalk at contesting.com
>>>> http://lists.contesting.com/mailman/listinfo/towertalk
>>>>
>>>>
>>> _______________________________________________
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