[TowerTalk] Hygain LP-1010

[kc4pe]

Hey Guys ..I'll jump in ...I needed a good spotting antenna on that 
would cover 10 through 17 meters ... no traps, solid construction,etc... 
I ran the figures on different logs and was disappointed with what I 
saw. I went with a design close to the Tennadyne T12. Now, I'm lucky to 
have a test/you build it 70 foot tower with a up down trolley.As I was 
building and testing I noted that height above ground made a 
considerable differential, but the computer would not verify what I was 
seeing. Once I established the construction, I trammed it on a 145 foot 
tower...and after numerous pull ups and downs, the log antenna said it 
wanted to be at 107 feet...so up it went on a 45G ..leveled at 107 
...Now I'll tell you .. it works and works well, within a S unit of 6 
elements at 145 on 20...closer to a 4 element Quad at 76 feet...Also I 
need help on 17, so I built a W2PV with three elements...at 70 feet the 
log smiled at it....

Don't ask me how or why...but to answer the question, if I really wanted 
a log, I would get a T-12 at 100 to 110.

And one day if Mom said...Hey Only 1 tower...it would be a T-12 type on 
a up/down trolly on a freestanding 55G.

73 ..

Bill ... KC4PE


On 6/14/2017 9:31 AM, Paul Christensen wrote:
>> "Maybe it’s a myth but I've always understood LP's to be equally poor everywhere. Not great FB - nor gain.:
> A myth equal to that of all vertical antennas being poor radiators in all directions.  Of course, verticals are often poor radiators when the other half of the antenna is missing or there are appreciable ground losses from poor or missing radial systems.
>
> My experience with LPDAs has shown very good F/B of at least 20 dB on all bands from a Tennadyne T14-HD.  The #1 caveat with the LPDA is that the gain-to-boom length ratio is poor.  While the T14 has a 42 ft. boom, 4Nec2 shows that 90% of radiated power comes from 2, and sometimes 3 active elements from the string of 14.  Some literature I've read indicates that all elements are active from a traditional LPDA.  Well, they are - but the majority of elements are not very active at all.  This is seen during NEC modeling.  In effect, the LPDA's performance is roughly equal to a 2-3 element full size Yagi on a short boom.
>
> BTW, the Tennadyne web site shows 8.5 dBd of free-space gain for the T14-HD.  Not even close.  It's actually about 5.5 dBd.  Using W8IO's LPDA modeling software, I calculate a boom length of over 200 ft. with normal sigma and tau values to get that kind of gain.  Why?  A 200+ ft. boom means that the active elements are now spread out over perhaps 30 ft.  The only viable way to construct such an antenna is with wire elements strung between two large supports with no ability to change directions.
>
> Probably a better solution is the newer optimized LPDAs since in the amateur service we don’t need continuous, end-to-end coverage from our antennas.  Despite the limitations of the T14-HD, there were some practical reasons why we chose it over other types but that can be discussed in another thread.
>
> Paul, W9AC
>
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>   
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> Original Message-----
> From: Richard Thorne
> Sent: Tuesday, June 13, 2017 2:12 PM
> To: Towertalk
> Subject: [TowerTalk] Hygain LP-1010
>
> Anyone have any experience with a Hy-Gain LP-1010 ( 10M through 30M
> coverage)  Looking for mechanical and performance info.
>
> Rich - N5ZC
>
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