Topband: horiz TLDL for 80m
Bob K6UJ
k6uj at pacbell.net
Sun Jan 8 08:35:13 PST 2012
Hi Guy,
You are pretty close Guy ! My little lot is only 65 x 120. I have two masts for supporting the lower leg of the delta One is
at the rear corner and the other is at the front corner set back about 20 feet. They are right next to the fences.
The tower is located about 60 feet from the back fence behind the house as you can
see in the picture. With the apex of the delta suspended from the tower the two
ends of the horizontal leg span diagonally across the property and attach to the
two masts. I don't have a lot of room to play with and hope I can get a slightly smaller loaded delta loop to work.
The tower is a US Tower HDX589MDPL which is 89 feet fully extended. A 16 foot chrome molly mast gives me a total
height capability of 105 feet. My property width of 65 feet really limits where I can run the horizontal leg of
the delta loop. Maybe with some success at modeling a smaller loaded loop will give me some more options.
73,
Bob
On Jan 8, 2012, at 12:12 AM, Guy Olinger K2AV wrote:
> Hi Bob,
>
> I had a look at your QTH via Google Earth. Would appear that the only
> support you have is your tower. And on something like a 65 x115 corner
> city lot. How tall is your tower?
>
> 73, Guy K2AV
>
> On Sat, Jan 7, 2012 at 10:08 PM, Bob K6UJ <k6uj at pacbell.net> wrote:
>
>> The reason I am trying a horizontally polarized delta loop is because I
>> had a vertically polarized delta
>> strung from the tower and it was too noisy. The tower was reradiating
>> noise to the delta. I am using a wood pole extended out 4 feet from the
>> tower
>> for the apex support and the lower section slopes away form the tower
>> about 30 degrees. I did a temporary lash up with feed at the bottom for
>> horizontal
>> polarization and 2 to 3 units quieter on the noise. Now I want to try
>> linear loading to reduce the size a little too. I would rather have the
>> vertical
>> polarization for DX but don't like the higher noise level. So its all
>> about the noise.
>>
>> Bob
>> K6UJ
>>
>>
>>
>>
>> On Jan 7, 2012, at 5:02 PM, Herb Schoenbohm wrote:
>>
>>> Bob,
>>>
>>> IMHO what you described would be a linear loaded loop and the folded
>>> down wires should be at the top and the feed where you described. This
>>> avoids some feedline interaction. But remember such an antenna
>>> depending on spacing from the tower will couple significant energy to
>>> the tower itself. So all bets are off on getting mostly horizontal
>>> polarization. The loop itself, even feed at the bottom center will
>>> still have some of that. My suggestion, but you should model it first,
>>> is to pull the bottom section away at a 45 degree angle from the tower
>>> so you have a sloping Delta Loop. This would probably help reduce tower
>>> interaction a bit. But the most ardent supporters of Delta loops
>>> recommend wooden support poles and corner feeding for best DX work since
>>> the vertical component is what really helps you on the low bands.
>>>
>>>
>>> 73
>>>
>>> Herb KV4FZ
>>>
>>>
>>>
>>>
>>>
>>> On 1/7/2012 8:29 PM, Bob K6UJ wrote:
>>>> I am panning to try out a top loaded delta loop for 80 meters strung
>> off the side of my tower.
>>>> I want to have a horizontally polarized loop. I will feed at the
>> middle of the bottom horizontal leg.
>>>> Does the loading wire attach to the apex at the top on this loop ?
>>>>
>>>> thanks,
>>>> Bob
>>>> K6UJ
>>>>
>>>>
>>>> _______________________________________________
>>>>
>>>
>>> _______________________________________________
>>> UR RST IS ... ... ..9 QSB QSB - hw? BK
>>
>> _______________________________________________
>> UR RST IS ... ... ..9 QSB QSB - hw? BK
>>
> _______________________________________________
> UR RST IS ... ... ..9 QSB QSB - hw? BK
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