Sat Antenna

[jazzboypro]

Hello,

I bought this antenna and i should get it somewhere next week. I plan on mounting it on a camera tripod or something similar. I will use the antenna with an Anytone 878UVII Plus. I was thinking of using about 15 feet of coax for the feedline. What coax would you recommend for this application ?

Many thanks
73 de va2fcs

 

[dkcorlfla]

Hello,

I bought this antenna and i should get it somewhere next week. I plan on mounting it on a camera tripod or something similar. I will use the antenna with an Anytone 878UVII Plus. I was thinking of using about 15 feet of coax for the feedline. What coax would you recommend for this application ?

Many thanks
73 de va2fcs

I had one of those a while back, great little hand held LEO (low earth orbit) satellite antenna. The tripod mount will not work for LEOs they move fast and the polarity changes during the pass.You will need to free hand it turning and twisting while tracking using a laptop and a ht will also have to adjust for dopler unless you hook the radio up to the laptop. The tripod would be useful for long range portable repeater access if that is something your interested in.

 

[jazzboypro]

I think the 878UVII Plus can automatically adjust for dopler. Any recommendation for the coax ?

 

[dkcorlfla]

I think the 878UVII Plus can automatically adjust for dopler. Any recommendation for the coax ?

I did run a search on the rig and see there is a YT video on auto sat Doppler. I did not view it but it should help you with how it works.

I would hold off on the coax for now as I believe the Arrow Yagi comes with a short section to be used with the antenna in one hand and the HT in the other. That's what I would recommend, just go outside in a clear area during a pass and see what you can receive. It's a lot of fun and I think you will see why the antenna needs to be hand held. If it does not come with the coax just order up a short jumper with the correct connectors. RG8X at only 3 feet long with have very little loss. Better cable will not make a difference at such a short section. Just be aware that RG8X is available in cheap solid center conductor or the much better and flexible stranded. Go with the stranded for sure.

 

[jazzboypro]

It's not clear if the antenna comes with a piece of coax or not so i'll wait until i receive the antenna. I will definitely look at some videos during the weekend.

 

[vagrant]

For 15’ of coax and your planned usage, I recommend LMR-240UF. That coax is stranded, thus the “UF” ultra flex. Regular LMR-240 has a solid core and it is stiff. Avoid that.

1. I use an Elk log periodic antenna. It has a wider beam width that makes it easier to capture and hold satellites.
2. The passes are relatively quick, so I hold the antenna in my hand.
3. The Arrow antenna has improved gain, but that comes at the cost of being more directional. This is in part due to the additional elements. I have compared these antennas first hand. Also remember that there’s not much in the way between you and the satellite.

* Another benefit of the Elk log periodic is that the 2m and 70cm elements are in phase. For terrestrial stuff, most antennas are vertical. The Arrow would need to shift 90 degrees to switch from 2m to 70cm or there can be a loss of 15dB or more on one or the other band out of phase. Additionally, the Elk does not require a diplexer, or “duplexer” as Arrow calls it. Perhaps Patrick @wd9ewk will chime in as he works satellites infinitely more than I. Search via Google using his callsign WD9EWK to get an idea of what gear he uses and how often.

* If you neglected to purchase the diplexer with the antenna, you will only be able to monitor/connect to one row of elements at a time. Not a problem if you only intend to listen.

 

[dkcorlfla]

I had the thought: that rig has Bluetooth so perhaps it uses an app on a smartphone to syn the Doppler shift to the satellite being tracked. If that is the case it would make for a nice light compact portable setup.

I hope the OP will post updates as you have me curious now.

 

[merlin]

May be OK for OSCAR or ISS

 

[jazzboypro]

For 15’ of coax and your planned usage, I recommend LMR-240UF. That coax is stranded, thus the “UF” ultra flex. Regular LMR-240 has a solid core and it is stiff. Avoid that.

1. I use an Elk log periodic antenna. It has a wider beam width that makes it easier to capture and hold satellites.
2. The passes are relatively quick, so I hold the antenna in my hand.
3. The Arrow antenna has improved gain, but that comes at the cost of being more directional. This is in part due to the additional elements. I have compared these antennas first hand. Also remember that there’s not much in the way between you and the satellite.

* Another benefit of the Elk log periodic is that the 2m and 70cm elements are in phase. For terrestrial stuff, most antennas are vertical. The Arrow would need to shift 90 degrees to switch from 2m to 70cm or there can be a loss of 15dB or more on one or the other band out of phase. Additionally, the Elk does not require a diplexer, or “duplexer” as Arrow calls it. Perhaps Patrick @wd9ewk will chime in as he works satellites infinitely more than I. Search via Google using his callsign WD9EWK to get an idea of what gear he uses and how often.

* If you neglected to purchase the diplexer with the antenna, you will only be able to monitor/connect to one row of elements at a time. Not a problem if you only intend to listen.

Thanks for the info. I did order the one with the diplexer. I should get the antenna somewhere next week and the weather is getting much nicer over here so i should be able to play with this soon.

Ideally i would like a setup that would allow me to use my 9700 but it gets expensive pretty fast.

 

[vagrant]

It does add up pretty quick. I was able to score an M2 Satpack1 at an amateur swap for $125. Definitely not as good as some yagi’s and rotor that automatically track a satellite across the sky, but useable. Something like that would work with your 9700.

 

[dkcorlfla]

I watched a YT video last night on the Anytone 878. The satellite keplerian elements are loaded direct into the 878 using the CPS software and a cable from a computer (does not use Bluetooth for this) then the math is done in the firmware of the 878 and a small display shows the sat location on the HT itself. No smartphone used.

Kinda amazing to me. I would have thought at least a smartphone would be needed but no it is all done within the HT.

 

[jazzboypro]

I watched a YT video last night on the Anytone 878. The satellite keplerian elements are loaded direct into the 878 using the CPS software and a cable from a computer (does not use Bluetooth for this) then the math is done in the firmware of the 878 and a small display shows the sat location on the HT itself. No smartphone used.

Kinda amazing to me. I would have thought at least a smartphone would be needed but no it is all done within the HT.

Yes i did download the Keplerian elements, did not have the time to play with the satellite function yet but the weather is getting warmer over here so i should be able to experiment a bit.

 

[jazzboypro]

Received the antenna today. It came with the coax and the duplexer is already installed and hidden under the antenna foam handle. I just had to assemble the antenna. I will give it a try in the coming days