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J-pole Sr update

J-pole Sr update

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UPDATE #2:

If you don’t want to read the whole story, the short version is the Alpha Antenna J-Pole Sr. is another very good antenna for many situations. I give it the same 5/5 rating as the J-Pole Jr.

The 34’ model of the Alpha Antenna J-Pole is now the J-Pole Jr. They have added a 60’ version which is now the J-Pole Sr. Because of my satisfaction with the 34’ model I decided to get one of the 60’ versions based on my thinking that the more wire you have in the air the better. That seems to hold true with this antenna.

My intention was to do a good A/B comparison with the same G5RV used in my review of the 34’ model. However, Japanese pine beetles killed the tree I had the G5RV hung from and it had to come down. The only tree I have left is a large oak tree which happens to be in a perfect position to hang the J-Pole Sr. but not a G5RV or any other “full size” antenna. The matching unit end of the antenna is hung at 32’ with the far end of the antenna at 5’. Since I now have only one “antenna tree” I can’t do an A/B comparison with the J-Pole Jr. either.

At least for the time being the J-Pole Sr. has now become my primary antenna and it is doing a great job for me. Most of my operation is on 40m, and my regular group hears me just as well or better than they did on the G5RV. In general it is outperforming the only other antenna I have, a HyGain 18-AVQ vertical.

The J-Pole does have one definite advantage over the now gone G5RV and the vertical; the J-Pole covers all the bands from 160m to 6m. My G5RV would not cover 160m or 30m, and the vertical does not cover 160m, 60m, 30m, 17m, 12m, or 6m. Of course the J-Pole is probably not very efficient on 160m, but I have made contacts with it out to 240 miles.

The bottom line is that if you need a good multi-band antenna and don’t have mounting options for full size resonant dipoles this antenna may be a good choice. It is certainly working for me.

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UPDATE:

I had the opportunity to use this antenna for portable operation from Destin, Florida for four days in mid-June. The only operating I did was participating in my regular 40m group in the morning. (We were with the family at the beach and ham radio time was limited….) Our group is mostly in west Tennessee with some stations in the northern half of Mississippi and one in central Florida.

The J-pole was set up with the feed point end at 24’ and the low end at 8’, about 150’ from the Gulf of Mexico.

I was able to hear everyone almost as well as with my home station in southeast Alabama. They were also able to hear me fine with me running 100 watts. Total setup time for the antenna was about 10 minutes. It took longer to pack everything back up only because I had to clean the salt film off everything.

Everything in the original review still stands. This is an excellent “field expedient” antenna which is easy to deploy for portable operation and well worth consideration for a permanent antenna if you don’t have the space for a full size dipole. I am well pleased with the performance I had with 40m at the beach. I still give it a 5/5 rating.

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Yes, I like the antenna, yes I am glad I purchased it, and yes I would do it again. The Alpha J-pole Sr. meets my expectations and I give it a 5/5 rating. If your situation is such that you don’t have a 40’ mast (or tree limb) and a 120’ of horizontal space or CCR problems you should definitely have this antenna on your list of possibilities for getting on the air. If you don’t like long reviews you can stop here….

Making A/B comparisons on antennas is a little like comparing a motorcycle to a car. Both will get you where you want to go but the experience is different. There are so many variables in comparing antennas (height, orientation, surrounding objects, feedlines, etc.) that it is hard to make a valid comparison in the field. What follows is my best effort to give you a feel for what the Alpha J-pole Sr. can do.

For the numbers below I have the antenna deployed as a sloper with the high (feed point) end at 30’ and the low end at 10’. The feed line is 100’ of RG8/U. The comparisons are against a G5RV type antenna with the center at 40’ and the ends at 12’.

Maximum SWR across each band as deployed:
160m – 5:1
80m – 2:1
60m – 2.5:1
40m – 1.7:1
30m – 1.4:1
20m – 2.2:1
17m – 1.4:1
15m – 1.5:1
12m – 2:1
10m – 2.7:1
6m – 3.3:1
The tuner in my TS-2000 will tune all the bands with no problem.

Receive comparisons listed are s-meter readings on my TS-2000. Yes, I know that isn’t worth much but it is all I have. There were actually a few cases where the J-pole had a stronger signal than the G5RV but the numbers below were what I encountered in most cases. It’s like I said above about motorcycles and cars and comparing antennas. Sometime the motorcycle wins but most of the time the car is more comfortable….

The numbers below are how many s-units the J-pole is below the G5RV:
160 – don’t know, my G5RV doesn’t cover 160
75 – 2 to 4
40 – 0 to 2
30 – don’t know, my G5RV doesn’t cover 30
20 – 0
17 – 0
15 – 0
12 – 0 to 1
10 – 0 to 2
6m – not tested

On transmit the numbers seem to be following the receive numbers fairly closely.
The numbers are how many s-units the J-pole is below the G5RV as received at the far end with stations who helped me with the A/B comparison:
75m – 3 to 4
40m – 2 to 3
30m – don’t know, my G5RV doesn’t cover 30
20m – 0 to 1
17m – not tested
15m – 0 to 2
12m – not tested
10m – 0 to 2
6m – not tested

My G5RV does not cover 160m so I can’t compare. I did make one contact at about 175 miles, but the other station who I could hear at S7 could just barely hear me at S2. That is not a surprise though. With a 34’ radiating element the J-pole has to have a very low efficiency on 160m. That being said you can load the antenna on 160 and I did make a contact.

I will be using it primarily as a portable antenna at two locations I visit a few times a year. Most of my operating is on 40m. At one location a full size dipole would be impossible to use and very difficult at the other. The J-pole is an excellent solution for me, and it will get me on the air from 80m to 10m rather than just 40m.

My testing is certainly not “lab grade” but it does indicate to me that the Alpha J-pole is a well-designed antenna that does what it is supposed to do. Keep in mind that “your mileage will vary” depending on how you have it deployed.
WB4MIO