Hello again fellow hams, info needed with regard to an odd antenna design?
Dear fellow hams,
I did a little downtime research and came acrosss this odd hf multibander from the not too distant past, it's published under the heading of an 8 or 9 band multiband Zig-zag antenna by VE3FKW as an omni radiator for the HF bands from GQRP archives.... Has anyone any comments re this design of hands on user experience that could shed some light on this mongrel?
Be happy, God bless, Mark., M6AWG.
Do you have a link to an article or something?
I can load up a pair of knitting needles (if they're aluminum) on 8 or 9 bands, with the right tuner...
A government which robs Peter to pay Paul can always depend on the support of Paul.
-- George Bernard Shaw
Yes a link to something that doesn't require you to become a member to get access to?
Can you load a picture or diagram to the QRZ page?
That would help. Have never heard of this antenna however there may be an antenna that is similar but called something else.
Get back to us with the information.
Yes, i do have a link, but i have to encompass the whole of the GRPQ issue? It is tedious, just google the callsign and antenna, and maybe some bright spark will guide the answers we seek...
Tired, Sleep well, M6AWG./
Try this link, then it's on page 6.
Pls take a look and give me some thoughts.
Best 73, M6AWG. Mark
Hi Mark, well that is a different looking antenna. I don't see anything that would make it work any better then a simple dipole. I will admit that I have no modeling capacity so this is just an opinion. What would be interesting is to compare it against another antenna. The boast of having a DX capability isn't really a test that has validity as would the statement that you can work anything you can hear. Band conditions are more of a contributor to performance at that time and place and under good conditions the world can be worked with very modest antennas. Haven't a clue why there are coils placed inside the copper pipe. That doesn't make much sense. Having a low SWR on 21 and 28Mhz should raise some eyebrows. There is no mention of the performance on 24Mhz and if the SWR is also low on that band that would translate to having losses somewhere.
Keep in mind the performance of an antenna like this is not based on any new applications of RF radiation. There are very well known applications for antenna performance and it's a subjective topic within the amateur ranks. Everybody will tell you their antenna is the best thing but that is usually arrived at by opinion not fact.
In smaller antennas there are limitations and trade offs. You can have any two of the following three items with a small antenna.
1. Good efficiency.
2. Wide bandwidth.
3. Small size.
So if you want good efficiency in a small size you lose bandwidth. Want wide bandwidth and good efficiency then you lose small size.
There is no magic that makes an antenna work better in a small size. Sometimes what you get is the shield of the coax is radiating and making a small antenna seem better than it is.
I am running a small sized antenna for 80-40 meter coverage. It's a magnetic loop and it gives up wide bandwidth to make it a workable antenna. On the 80 meter band just changing to the opposite sideband and you would have to retune the antenna. If I used a larger capacitor it could work on 160 meters as well. Efficiency is reduced and the bandwidth is extremely narrow, in the order of 700Hz. Making the loop bigger yields more bandwidth.
Now you could be the one to make the antenna VE3FQW has published and also have an antenna that would work as a reference. You can then measure the performance and make valid conclusions about it.
There are always amateurs looking for that special antenna that is cheap to build, small in size and out performs everything presently in use. That hasn't happened otherwise the entire amateur community would find out about it and they would be using it. Have never heard of the VE3FQW antenna and as I have stated, if it was such a good antenna everyone would have one.
Hope this helps
The "antenna" is more of a transmission line than an antenna.
The operating principal of the VE3FQW antenna has been "re-invented" many times. (Only the shape changes to confuse the reader.)
Unfortunately this antenna cannot be analyzed by NEC because of the coils, open on one end, and placed inside a metal tube. On 10 and 15 meters it is possible to get some unexpected resonant points because of these coils. (The same thing happens when you make a dipole out of coax, feed only the shield and short the center to the shield at the ends.) So there could possibly be resonances at 10 and 15 meters, however I would expect the feedpoint impedance to be very low.
On the lower bands, this antenna will operate on feedline radiation. A balanced antenna with an impedance consisting of a very low real part and a high reactance, and no choke on a coax feedline, is a recipe for high common mode currents. Radiation from the feedline will be much greater than anything from the "antenna". On the high bands, due to the way the antenna is fed, a large amount of radiation from the antenna is cancelled by the mostly parallel elements. (Check the way he connects the coax.) That should result in a very low feedpoint impedance and with no choke, I would also expect to see common mode currents having a large effect on 10 and 15 meters.