Thank you very much for the info. Mine will go up this summer on my 50' tower and has been a lot of work. Your review gives me the want to get it finished up!
My simulation of the hex-beam using 4nec2 shows that the input impedance is about 23.5 ohms (height = 70 feet) resistive at resonance which gives an SWR of 2.14 when fed with 50 ohms. This is not a big deal, but some rigs may need a tuner for proper operation. Incidentally, the main lobe antenna gain over typical soil ground is 11dBi. Takeoff angle at 70' is just over 15 degrees (20 meters). Front - Back is 16dB. Front - Side is 22dB. Also, if you get the MFJ-1848 (added "dipoles" for 40 and 30 meters), you should be aware that the input impedances of these elements are about 17 ohms (SWR of 3.0 when fed with 50 ohms). Antenna is bidirectional, and the main lobe gain is 7dBi. Front to side is about 9dB.
I would be interested in seeing your SWR measurements. If they are quite low, there must be a matching section on the element feedpoints. My guess would be a simple hairpin match.
In got mine yesterday, as I started to assemble it I found It was missing several parts. I immediately called MFJ and reported the the missing parts. I fully expected to receive an apology and a promise to send the missing parts immediately. Instead I got we (MFJ) didn’t make the antenna and they would forward my problem on to Hy-gain. And after that nothing. So now I paid $600 for an antenna that is unusable. I can go down to the local hardware store and get many of the missing pieces but one of the missing pieces was the feed line balun (they don’t carry these at my local store). I am getting ready to box it up and send it back to MFJ (I ordered directly from them). Frustrated and disappointed! Buyer beware!!
Mike Harnett ; that's what I want to know too. I'm skeptical with the standard cables. Other makers sell winter extra stong cables to hold this fibre glass rods.
All modern transceivers use 3dB per S-unit. The manufacturers ALL want to make their radios look better on receive. To get accurate comparison readings on receive signal strength you need a resistance ladder calibrated in 1 dB steps. Lock out your transmit or you Will smoke the box (ask me how I know after 60 years of playing with antennas)
You could have adjusted the different antenna parts while you had the antenna on a short service pole before you set it up on the top of the support tower .
Dave, do you know anything about the nature of the signals to and from the rotator? This might be a Raspberry Pi or similar project. In software, you could rename the points anything you like. 73 DE WA8YCD
Thanks for video. Concerning reported gain most of the manufacturers do not scale properly their s-meters (they are rather optimistic). If S9 is usually close to 50uV level going down this is more by 3db and not 6db between the units. So 2S difference is more likely 6db actually which is closer to the theory. As you I am jumping into the beams and rotators as well and I've got a …. hexbeam too. See you on the air from Tom AG7JQ
Nice video and update. I have a tri-bander but don't have coverage for the WARC bands. I was a little taken back with the $500 price-tag and was wondering how hard you think this beam would be to homebrew and if the low-end of 6-meters could be fixed (I assume by lengthening those elements slightly)? Thanks Dave & 73!
Thanks for this video! Just few things i missed in this series of videos. 1. You stated spreaders were plastic in assembly video. Did you mean fiberglass? 2. What type of wire was provided for the elements? Looked like bare wire. 3. How did you ground your mast? 4. How did you ground your rotor control wires? Thanks again.. Jim SW Florida
I think the spreaders were fiberglass because of how it broke: very messy, not a clean break. The wire is bare wire. Right now the antenna is up temporarily, so I don't have good grounding solutions yet.
Dave I have the vertical you do but not happy with it. Have you done a video on it if so want to see it. Maybe mine is off somewhere. Only band it works okay is 40m. I think I will pick up one of these Mfj hex beams
The difference between a 2 and 3 element Yagi is about 2dB. With typical signals, that is less than an S-unit. However, with a very weak signal it's the difference between solid (with some difficulty) copy and zero copy. It's been said that every 2dB uncovers another layer of DX.
The most commonly used impedance measuring tool for antenna work is an SWR analyzer. There are other vector network analyzers out there, but most people use them for the SWR.
vertical antenna, used for short skip communication, with its much lower angle of adiation is not the antenna you should be using for this comparison. EUdx reports would be a much better comparison. You sound like MFJ antenna promoter! With over 45 yrs experience, while working in RF field, I find your videos, just simply entertaining- nothing else /guess you were working in a commercial radio environment in the past /. So this is a critical comment OG . Regards Jack vk5cjc
Thank you for nice tutorial video I want to and would strive to attain my hex beam as well. My question would be since you mentioned about 3 wires on the rotator controller I got a YaesuG450XL and wanted to know which and how I would connect in order for it to work. I do have an old connector that goes on the tower where the rotator would be that is Yaesug450 but the controller I would use is yaesug450xl. Thank you and I hope to hear from you 73 de KH2ZZ
so u know u can get shielded cat 6 8 wire for less than 20 dollars that works real well u can even double the wires so u got even better amp draw on the rotor saved yourself a lot of money and it works great i am doing this on my rotor which i have a channel master 9621hd rotor
please wear a hard hat next time you erect an antenna mast. A falling rotor or bolt off the antenna can hurt or even kill you if it hits you in the head from a 20-30 foot drop.
