Sirio GPS 27

[eyecue]

The SWR on this antenna pegs my meter, an ohm meter shows it as a short. There is a coil in the base, the manufacturer is on holiday break and the seller tells me to adjust the tip length. My VNA is not here yet. Any ideas?

[nosaj]

Put cable on dummy load measure swr for cable then proceed to antenna.
Nosaj

[eyecue]

I ruled out the cable right off the get go.

[MDYoungblood]

The Sirio GPS 27 is a 1/2 wave without ground radials, you already knew that but some others may not have.
With Sirio base antennas getting the dimensions right is a key point and with them I always suggest building it on the ground first and get the SWR where you want it before putting it up permanently. The only part on the antenna to tune is the very top section.
Which dimension did you use? Use a MM to inches calculator on the computer to cypher these dimensions.
Another little known fact for these antennas with no ground plane is the coax needs to drop straight down below the connection point 6 to 9 feet and if you plan to use a air choke (dirty choke, coiled coax choke, it has other names too), it needs to be below that point, not right at the connection.

3's

Greg

[nosaj]

I ruled out the cable right off the get go.

Well not everyone does, so I threw it out there since it's simple to test with a dummy load.

nosaj

[ExtraClass]

Great information as I have one of these antennas on order from Amazon and should receive it in few days.

[MDYoungblood]

It is a shame he never came back to tell us what the problem turned out to be.

3's

Greg

[eyecue]

THe problem vanished as quick as it came. I have no idea what it was. VNA and SWR are all good now. Dealer offered to replace the coil, factory support was lacking.

[nk14zp]

Moisture in the base of the ant?

[MDYoungblood]

Sounds like there was a connection problem more than the antenna.

3’s

Greg

[ExtraClass]

OK, Got my Sirio GPE 27 5/8 antenna with ground radials all set up with a nice low SWR (1.2/1.3) acrossed the channels and works really well.

Since I live in one of them HOA covenant communities, I only have it up a total of 27 foot to keep my profile low, up over my roof top and happy with my incoming/outgoing signals! :D