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Chad
Senior Member
Username: Chad
Post Number: 1033
Registered: 11-2004
| | Posted on Tuesday, August 15, 2006 - 10:01 pm: | 
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So I got the updated grounding in for the tower/rig (comon, try it now Ma Nature) and the conduit buried for all the coax, the conduit in the shack for the coax thru the wall and the new scanner antenna up. I am now ready to go for a 2/70 antenna (dual band). First of, things in HAM world can get expensive, no doubt, but I have thought about building the "copper cactus dual band J-pole" Anyone done one, can anyone comment on the quality of emission and receive from say a commercially bought dual band fiberglass model (diamond or equivalent)?
I have fabrication abilities and the facilities to do it. Is it best to jump right in building or get on the air then work your way up?
The money I save on antenna (providing they perform equally) i can drop into a radio, I have my heart kinda set on the Yaesu FT-857D, it's not cheap but a penny saved is a penny earned and I have come into a proposition to make a little (actually great!) extra cash (new band to work for).
Antenna builders unite, a 2/70 is small so what better to start with other than the tolerances are tighter?
ALSO.. I'm gonna need a good meter (SWR) to know how it's working and tuned, I'm assuming my 11M won't work? It's a para dynamics 600. Any affordable recommendations?
Chad |
Bruce
Senior Member
Username: Bruce
Post Number: 3991
Registered: 9-2003
| | Posted on Wednesday, August 16, 2006 - 6:43 am: |
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Yaesu FT-857D
NICE RADIO ...... |
Chad
Senior Member
Username: Chad
Post Number: 1034
Registered: 11-2004
| | Posted on Wednesday, August 16, 2006 - 9:13 am: |
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Yeah it seems to have what I want without running into the "botique" area of color TFT screens and all. It has gotten great reviews so it looks like a winner in my book, The IC-706MKIIG was another but more pricey and has not gotten as favorable of reviews.
Chad |
Bruce
Senior Member
Username: Bruce
Post Number: 3993
Registered: 9-2003
| | Posted on Wednesday, August 16, 2006 - 9:59 am: |
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I have a 706 and the 857 is as good at less money
Now I have a TS-2000 I may put the 706 in the car .... |
Chad
Senior Member
Username: Chad
Post Number: 1035
Registered: 11-2004
| | Posted on Wednesday, August 16, 2006 - 11:04 am: |
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The Icom IC-7000 looks pretty Yyyyummy too! It's out of my price range but close to that of the TS-2000. Regardless, I think the 857D will make a darn fine "first radio" 
Now..... Have you used J-Poles?
Chad |
Bruce
Senior Member
Username: Bruce
Post Number: 3994
Registered: 9-2003
| | Posted on Wednesday, August 16, 2006 - 12:11 pm: |
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J-Poles are VERY good simple antennas ...... not going to work like a 10 elm wide space beam but Iv'e used them on 6 2 220 and 440 with good results.
Everyone with the 857 loves it .....
I have a FT-100D it is the grandfather to that 857 and it has good points some VERY good ones however DO NOT BUY A FT-100 or 100D ..... they have a very high output transistor failure rate.
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Slugo4449
Intermediate Member
Username: Slugo4449
Post Number: 104
Registered: 7-2004
| | Posted on Wednesday, August 16, 2006 - 2:00 pm: |
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I have built and used different types of copper cactus antennas.
From my experience the copper cactus J-pole out performed a ringo on 2 meters. That was the only ringo I had to test against.
I have built tri-band j-poles with a single feed (tricky) a couple of dual-band single feed (2 meter/440)and the famous 2 meter J-pole that will also work 440mhz on a harmonic. They are fun to build and also work.
The big problem is the price of copper pipe now. I used to get a 3/4 inch, 10 ft section from Home Depot for about 10 dollars. I just checked and it is about $24.00 per 10 ft section now. The elbows and joints are also high priced too.
Using a search engine you can find all sorts of photos and intructions/diagrams on the internet by typing "copper cactus antenna" or "copper cactus dual band antenna" or even try "copper cactus triband antenna". The more bands on the same J-pole the harder to get it to resonate on the frequencies you want.
You know you can also make them out of inexpensive twin lead and just hang them from a tree or the side of a building. Or even stuff it into a piece of PVC pipe and strap it to a pole.
Lots of fun to build as a project.
Marty
KG6QKJ |
Chad
Senior Member
Username: Chad
Post Number: 1036
Registered: 11-2004
| | Posted on Wednesday, August 16, 2006 - 4:09 pm: |
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Thanks Marty and Bruce!!!!
The price of copper is not as bad as the price of mass produced fiberglass and the marketing behind it
I think the one I was looking into was the 2M one that works 440 on a harmonic. A dual bander could come later with expierience, the tri bander is kinda moot with the 857D because 2/440 are on one output and 6M/HF on another. I would really like to see 6M selectable for which output but I'm sure there is a reason for the design and beggers cannot be choosers. I know it will not perform like a beam, I'm really looking for an omni anyway, I am smack between two larger cities in the sticks, I'd like to be able to talk to both and I have no rotor at this point or really much desire to go that route right now in this venture.
How about tools needed, the obviuus are the mechanical tools for the build, that's taken care of, but what is a good meter to do the tuning with? Affordable is good, but I'm not wanting something unuseable, I see antennas as expendable, eventually around here they will get broken or beaten by weather. Test equipment for building on the other hand will end up paying for itself in money saved from buying "pre-tuned" antennas. Like I say 2/440's are small, why not build? That's what it's all about right?
Chad |
Slugo4449
Intermediate Member
Username: Slugo4449
Post Number: 105
Registered: 7-2004
| | Posted on Wednesday, August 16, 2006 - 8:43 pm: |
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Chad:
You will need a pipe cutter, map gas(yellow canister) for the heat, some rosin, sand paper to clean the joints and some solder to sweat the joints.
Lay the J-pole on it's side on a couple of bricks and make sure it is squared up. Heat from the side, put the solder to the top of the joint and then when one drip of solder falls on the ground underneath it, the joint is sweated. Wipe immediatly with a dry cloth to make it look pretty.
If you follow the instructions on the web and you cut the pipe exactly right, then you will be very close to the middle of the 2 meter repeater part of the band.
The instructions will tell you where to tap into on the tuning stub and the radiator of the J-pole.
My first one came out resonating at 146.200 mhz.
I have an antenna analyzer but you can also get by with an SWR bridge.
When you use a regular HF SWR bridge, you can get by with it on 2 meters if when you go to the FWD position you can get it to go full scale.
Be exact with the measurments and you will be very close to where you want it to be.
Now an easier antenna would be a wire delta loop. You can feed it differently to get vertical and horizontal.
Those are fun too. I love to make antennas and wire is my best friend around here. I also use copper pipe and PVC pipe.
Now that I am all jacked up I am going out to the garage to make something new!
Good luck again,
Marty
KG6QKJ |
Goat373
Intermediate Member
Username: Goat373
Post Number: 269
Registered: 3-2005
| | Posted on Wednesday, August 16, 2006 - 9:06 pm: |
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if you buy...get a big repeater antenna with lots of gain for about 100 bucks...but id build...my copper j-pole(cut for ONLY 2 mtrs) works great on 2 mtrs, MURS, 220, 440, marine...its very wide banded. Sure there are spikes in there between them all somewhere, but once you know where they are its no big deal...all my swr spikes are in places i never talk anyway. use the design at N4UJW's design lab website.(just search for that call sign in google) that will build you a copper tubing j-pole at will work like a top ALMOST anywhere uhf/vhf that you have any business being |
Chad
Senior Member
Username: Chad
Post Number: 1037
Registered: 11-2004
| | Posted on Wednesday, August 16, 2006 - 11:16 pm: |
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That's just great news everyone! It sounds like a winner.
Marty, unfortunately I am all too familiar with soldering copper pipe I re plumbed a buddy's house after a power loss and a hard freeze. I actualy enjoy soldering for some strange reason, even though I do it all day. That is the #1 reason this antenna appeals to me. Easy and cheaper than the alternative, an of course a bit of DIY pride!
Chad |
Geekster
Intermediate Member
Username: Geekster
Post Number: 187
Registered: 6-2004
| | Posted on Monday, August 28, 2006 - 10:01 am: |
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[quote]First of, things in HAM world can get expensive, no doubt, but I have thought about building the "copper cactus dual band J-pole" Anyone done one, can anyone comment on the quality of emission and receive from say a commercially bought dual band fiberglass model (diamond or equivalent)? [/quote]
I have built the super J-Pole (similar to the cactus). I also have a diamond 8ft dual band antenna. The Diamond did outperform the super J-pole in my tests. I actually had better results using ladder line (very cheap and available at Radio Shack) for the J-Pole construction vs. the copper tubing. You can make the ladder line J-pole weather proof by inserting it into a PVC pipe and placing an end cap on it. A simple bolt or screweye can hold the antenna in the tubing. I used stryofoam (center drilled) to hold the antenna in place. I had the tubular style of 300ohm cable. I would recommend the 450ohm twin lead cable for UHF work. Mine was for the 2 meter band.
[quote]ALSO.. I'm gonna need a good meter (SWR) to know how it's working and tuned, I'm assuming my 11M won't work? It's a para dynamics 600. Any affordable recommendations? [/quote]
The Para Dynamics PDC 600 will not work for the VHF/UHF bands (insertion loss is too high). I had decent results with the MFJ power meters, although not the best construction. Daiwa makes a fine meter for 2meter and 440Mhz bands. Internet Auction Sites may be a cheap alternative to buying new. |
Chad
Senior Member
Username: Chad
Post Number: 1049
Registered: 11-2004
| | Posted on Monday, August 28, 2006 - 10:24 am: |
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Thanks Geekster! I'll keep your comments in mind!
Chad |
