Shack Antenna
Antenna used at the shack
HF Antenna
The 20 Metre Dipole
Most of the time I use a random long wire for simplicity, however sometimes the 20 meter home brew (courtesy of M0GGO) comes out. It’s a half wave dipole using a T shape piece of perspex in the centre, and a balanced line feeder. Given the low / no cost of production it works remarkably well, which just goes to show that keeping it simple works very well. It is also fits in to the pocket so it is great for portable use.
20 metre dipole
The Carolina Windom CW-20
This is a great antenna if you can get it high enough. A windom design antenna looks a bit like a dipole, but conductor is longer than the other, and there is a vertical component made of co-ax which comes down from the central transformer. At the bottom of the co-ax there is another matching transformer. The main problem that I have found with this antenna is that because there is a weighty transformer between the two elements it needs a substantial amount of tension to keep the wire straight. Each end was attached to a rope and put through a light duty sailing pulley, when I say light duty it is spec’d for 300Kg of weight. I had difficulty keeping the wire taught. Also the transformer catches the wind a bit more than the dipole. Due to the size of the garden it lives in the shed at the moment.
Carolina Windom CW-20 HF Wire
VHF Antenna
The 7 Element ZL Special
The main shack antenna for 2 meters SSB. This is a great antenna that provides a reasonable amount of gain, and takes less space thatn a conventional yagi antenna. The main point about this antenna is that both the reflector and the radiating element are wired to the feeder, but the reflector is connected with a small amount of ladder line and the polarity is reversed, so I’m not sure if it should be called a reflector :) Using 2.5w and 5w with a little lift reasonable contacts have been made into northen france from central england. It is in regular use for the VHFCC contests, - mostly by M3WFO who also shares the shack. The addition of the rotator saves me getting cold whist changing beam directions. The best directions from the current QTH in Dunstable are south west, and north west.
7-Element ZL Special VHF Yagi
Arrow 2 metre and 70 cm portable yagi
This antenna comes in to it’s own for satellite contacts. It is made by sandpiper and has 3 elements for 2 meters, and 6 elements for 70cm, it takes two feeds, thus 70cm vertical and 2m horizontal can be used at the same time. The elements all unscrew and it can be packed away for mobile use quickly, although labelling the elements is a must as the 70cm elements are very similar in size. Due to weather abuse though, it is now has 2 elements for 2meters, and 5 elements for 70cm. Nice and light for portable work though, and it doesn’t make your arm ache too much when trying to follow satellites with it.
2m and 70cm Yagi
Diamond X-200-N Vertical 2m and 70cm Vertical
Eveyones gotta have a white stick. This one seems to do thr trick for me. It’s possible to get in to 6 repeaters on 2m and 4 repeaters on 70cm when it’s up at 20 feet on the telescopic pole. My promary use for this antenna is for APRS and packet radio, whilst M3FWO mostly uses it for local repeater rag chews and nets. This is a good simple antenna which uses an N-Type connection.
VHF Antenna on telescopic pole
Entries (RSS)
RE: VHF Antenna 7 Element ZL Special
Just dropping a line to say many thanks for posting your comments in regards the ZL special.
I cannot find any professional review/s on the web. I’m considering to buy a yagi beam (5 or 7 el) for the occasional 2m contest DX and the ZL resulted as a possibility however i read on some forums that due to the precise design the performance could easily be altered if the feeding system is subject to strong winds/rain etc
Would you be so kind to let me know if you experienced similar issues? I guess is hard to believe all that is said on the web … the other option for me would be a classic 2m Yagi with the loss of few Dbd compared to the ZL
many thanks in advance
73 de Rod / 2E0RPS
Hi Rod,
Many thanks for your kind comments.
I didn’t have too much difficulty in setting up my ZL, although I’m sure it’s not perfectly aligned it seems to do the trick for me. The only adjustment I needed to make was to change the length of the matching stub, I’m using about 11cm of rg-85.
The main reason for choosing the ZL was that there was potentially more gain per boomlength over a regular yagi.
Cheers
Noel - M3OYQ
QSL Noel,
many thanks
73 de Rod / 2E0RPS
Just to inform you Noel,
I then purchased a 5 Elements Moonraker Yagi 144 - 146 mhz (gamma match) for £49.
so far i’ve been quite pleased by the built quality and easy assembly (no tools required). in terms of performance i can engage most London City repetares on Vertical polarization. Had few simplex up to 42 miles away (so far) with the aerial indoor beaming out my window and this was done with a 2.5 watts handheld connected to the aerial. That said i think the aerial is doing well but the real test will be on SSB when i get the chance to put it up on the roof.
obviously there are rooms for improvements. SWR 1.7 to 2.0 on most frequencies however quite sensitive to the surroundings.
73 de Rod / 2E0RPS
hi rob
my call is m6mjk my location is normanton west yorkshire
i hope you dont think im being cheeky but do you have any plans to build a 2 meter or 70cm yaggi as im on a budget so to buy one is out of the question 73s from m6mjk martin
Hello Martin m6mjk,
not sure if your messgae was directed to me (Rod 2E0RPS), pls check my qrz details and drop me an email if you like.
There are lots of information on the web in regards VHF/UHF antenna constructions. \ You can build one very cheaply.
73 de Rod / 2E0RPS
nice site very informative… thinking of a beam as main 2 metre antenna what’s your thoughts or d you think you need a vertical for local stuff. like to work stations without help ie repeaters etc..
Hi Nigel,
Thanks for visiting my site
I use the beam in horizontal polarisation for SSB and have it hooked up to a cheap rotator. It works ok with FM for _local_ repeaters, and if I change it around to vertical I can increase my repeater range somewhat, however it would be easier to set off other repeaters unintentionally if you’re not careful - especially when using a 1750hz tone rather than CTCSS
73
Noel, M3OYQ
Hi Nigel,
What I meant to say was that I use the _beam_ in vertical polarisation to get better range on FM repeaters, and in Horizontal for SSB, however when horizontal I can still get into the local repeaters reasonably with only a couple of watts. I’ve not measured the attenuation difference myself but I think I remember some one saying there was about a 60db attenuation between H and V. Trial and error tells me that GB3VA about 30km west of my home QTH comes in at S9 on a vertical, and about an S4 on the horizontal beam, although this looks like a 30db difference according to http://en.wikipedia.org/wiki/S_meter I wonder if the error is the remainder is a non-perfect setup + a bit of gain on the beam?
I do have a vertical 2m/70cm but recently I’ve taken it down to give it a good check over it as vswr seems to have risen pretty high on 70cm since the winter, but it’s still fine on 2m.
Apologies for being a bit slow on the response, I get some serious amounts of spam in the comments,
73
Good to see you on APRS - the dunstable area really needs some activity. i have some spare kit and will be happy to help you set an RF digi with it so that the M1 gets better coverage. Drop me a line if you are interested. 73 Steve