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Reviews For: JK Antennas JK 3040SR

Category: Antennas: HF: Yagi, Quad, Rotary dipole, LPDA

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Review Summary For : JK Antennas JK 3040SR
Reviews: 2MSRP: 4625
Description:
Coil loaded 4 element 40m and coil loaded 3 element yagi on a single boom. Dual Feed.
Product is in production
More Info: http://jkantennas.com/jk3040sr.html
# last 180 days Avg. Rating last 180 days Total reviews Avg. overall rating
0025
NS4X Rating: 2021-07-08
Outstanding product and service Time Owned: 6 to 12 months.
This review will cover my experiences with the JK Antennas JK3040sr yagi, which is a dual-band yagi covering 30 and 40 meters with separate feed points for each band. It is two JK monobanders (the JK 404C and the JK 303) combined on one boom.
Quality
The quality of this antenna is superb. Very heavy-duty construction throughout with no evidence of “cheap” components.
Construction-Installation
This is a big antenna. The boom is 36 feet long and JK’s website lists the weight as 215 lbs. The elements are long (longest is 49.5 feet) and very robust. Take this into account when planning assembly of this antenna. It is not trivial to reposition once fully assembled. In my case, I chose to assemble the boom and the element channels on saw horses and then assemble each element half, but leave the element halves unattached until the boom assembly had been moved into place near the tower. I did this so that most of the assembly could be done inside a shop in the shade and with a nice concrete floor to catch dropped hardware. This worked very well for me, but you should decide if it is best for your situation. Each element of this antenna uses a large aluminum coil that is very robust. Follow the instructions carefully, step-by-step; assembly is not difficult, but it is easy to forget to wrap the silicone tape that covers the fiberglass section before starting on the coil. You will be very annoyed if you discover this after you have secured a coil in place!

Another tip: stainless steel “hose” clamps are used to secure the element tips (bolts are used everywhere else). These are quality clamps, but it is fairly easy to strip them if you are too aggressive when tightening them. I would actually have preferred bolts to the hose clamps.

I hired a crane and a professional tower installer (K4ZA) to install this yagi at 100 feet on a rotating Rohn 55g tower. We had to get a bigger crane due to the first crane’s boom’s inability clear the long elements when lifting the antenna into position! The first crane had 130 feet of “pick”, but the operator failed to account for the horizontal clearance needed for the elements. Also, during this first installation attempt, during ground handling we broke a connector on the LMR-600 type phasing line that connects the two 40 meter driven elements. Be careful of this line when moving the antenna during installation.
Performance
On-air performance is outstanding on both bands. I do not live on an antenna range and so my assessment is subjective, but I have made several thousand contacts on 40 meters (I am a contester) and about 500 on 30 meters using the antenna since it was installed and I have found the front to side and front to back performance very satisfactory as well as being very happy with the signal reports I get on transmit. Plus, the antenna survived, with no ill effects, a moderate ice storm this past winter that kept the elements drooped for five days before the ice melted.
Customer Service
I cannot do anything but rave about the customer service. Ken at JK Antennas was always available to answer questions. Regarding the broken phasing line that I mentioned above: a call to Ken resulted in him shipping a replacement ASAP to my QTH. It was time critical due to scheduling the crane; Ken understood this and the phasing line arrived as promised!
Conclusion
If I had to do it over, I would order this antenna again. It is high quality and high performance. Assembly and installation are not trivial, but the performance is worth it.

N5ZC Rating: 2017-07-30
Excellent antenna Time Owned: 0 to 3 months.
I just installed this beast at 120' on my rotating tower. The workmanship is excellent, everything is heavy duty. Ken sent me two boom to mast mounts since it was going to be side mounted on my 55g rotating tower.

Mechanically this antenna is very well designed.

The antenna matches the spec's published. The SWR is as follows:

40m - 7.000 (1.5:1), 7.210 (1.5:1), 7.250 (2.25:1)

A tuner will handle the high end of 40m if I go that high.

30m - 10.1 (1.0:1), 10.150 (1.25:1)

FB is excellent as well.

If the RBN network is any indication, I should have an arsenal on 30m and 40m.

Rich - N5ZC