[AK-VHF] fixed satellite antenna question

[Ed Cole]

Brandon,

My guess is you only need four-turns on 144 and six-turns on 435.  Many 
methods to support the windings.

In 1996 made a 16-turn 437 helix using a closet pole as center support 
and 1/2-inch dowel legs to support the turns.  Probably should lacquer 
or paint the wood.  I used small tie-wraps to hold the wire to end of 
the dowel with small hole drilled for the tie wrap.

No. 12 solid copper house wire for the windings with a 1/4 wavelength 
long 1/4 inch wide copper strap (Home Depot) from coax connector to 
first turn.  Spacing of strap varies from center pin of connector out to 
about 3/8 inch from the reflector; adjust spacing for SWR match.

For the 437-MHz helix I bought an aluminum 15-inch pizza pan; for 145 
you could extend diameter of the pan with several wire spokes.

Such an antenna is not hand-held, but needs a rotator and support (tripod?).

GL, Ed

On 1/30/2023 5:24 PM, Ed Cole wrote:
> Brandon,
> 
> Satellites move fast in both az and el.  Many have set up with elevation 
> fixed at about 15 degrees as a good compromise.  You need less gain 
> overhead vs on the horizon.
> 
> I recall ISS only reached about 11-degrees in AK; I just pointed south 
> on horizon with 10-element yagi.
> 
> 73, ED - KL7UW
> 
> On 1/30/2023 4:18 PM, Brandon Clark via ak-vhf wrote:
>> This reminds me of how much I atill need to get my satellite antennas 
>> built. I'm planning to do a pair of helix antennas. The mounting will 
>> be an azimuth only rotator, with a manually adjustable elevation hinge.
>>
>> Do let us know how the antenna build turns out.
>>
>> Brandon Clark, KL7BSC
>> https://brandonclarklabs.com/
>>
>> Sent from Proton Mail mobile
>>
>> -------- Original Message --------
>> On Jan 30, 2023, 16:03, Curt Law wrote:
>>
>>> On Kodiak, I've worked some of the satellites and ISS using nothing 
>>> more than a 6db vertical antenna. Rarely do the satellite go above 30 
>>> degrees and that's well within most vertical antenna radiation 
>>> pattern. AL7LQ 
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