Flexradio and OCF 80-6m multi-band (Windom) - thoughts/experience?

Dave - N6XVZ

Bill English

I have an OCF for 80-6m that has given me good results. Made a lot of QSO's on 30m using the ATU, not a bad antenna. I put it up mostly for 80 and 40, but have made a lot of QSO's with it on 6m. You won't be disappointed.  

DaveC

Had a 80-6m OCF up for about 3 years with the vertical radiator. Tuned great 80-6. (with internal ATU) including 60m. Took it down because I moved. Of course, mine was outside up about 50'.

Bill English

I had one of those as well some years back, with the vertical radiator. It was up about 90 feet and worked surprisingly well. It was a good one.

Wayne

I have an amerirton sda100 1200 watt screwdriver antenna mounted on my roof. Its only about 6ft tall and remore tuned via control box from my shack covers 80m thru 6m all you would need is a few counterpoise wires from the base of ut across the attic, does really well on my roof and with just the antenna i get about 1.5 to 1 swr then i occasionally use the flex tuner to further match it to 1.2 swr or better. Had it up ther for over a year outside with no issues so in the attic it should do even better out of the weather. The only downside is it is about $450 new with everything needed.

Rick - W5FCX

I’m using the Ni4l OCF Windom and it works very well. The Buckmaster is also quite popular. Make sure you don’t have aluminum backed heat shielding in the attic, as it would negate your efforts (my new HOA house has it). Inside the attic steer clear of large metallic objects and house wiring, if possible, to prevent SWR and RFI issues (even if it means not running elements perfectly straight). I’ve had severe issues with GFCI breakers popping on 40 meters above 75 watts. Also if you’ll be running any power, antenna element insulation and clearance matters to prevent arcing and potential fire hazards. As always, verify maximum permissible exposure levels inside the rooms below the attic for safety, esp if running power, as the antenna will radiate inside the attic and beyond. Good luck. Let us know how it works out.

KF4HR

N8SDR

N8SDR

An OCF with a vertical radiator isn't really an OCF its a windom

AA0KM

Mark WS7M

Dave - N6XVZ

I've been eyeing the Ni4L as well.  I basically have a plywood deck but noticed two sections along the ridge that have aluminum foil about 1x4 ft - not sure why it's there but worries me for blocking part of the signal close to the balun.  The only other worry in the attic is the large volume of foil air duct (It's Texas) piled up onto the top of the mancave cube, a bit close to the peak....

I plan on a max of 100w but the concerns are valid to consider.

Thanks so much for the response and input!

Dave - N6XVZ

Thanks for the observations.  I suppose with an OCF I'd at least be on the air but with band conditions it might be quieter than I'd hope.  Ugh....  Great input - just what I'm looking for - real world input vs all the debates/information.  Thanks!

Dave - N6XVZ

Wow great stuff.  Thanks.  I'll check it out.  I wasn't aware of the RF issues so the 1:1 RF chock would be good input to have!

Thank you.

Dave - N6XVZ

Rick - W5FCX

DaveC

Did not know that. Learn something new everyday.

Jim Ricker

Ken - NM9P

Other options....

1) A secret "Flagpole" antenna - feed a 29-33 ft. flagpole at the base, with buried radials.  If you have an auto-tuner that can be concealed at the base with landscaping, all the better.  Just remember to fly your flag on the right days!

2) I like the wire under the facia/soffet dipole.  A 40 meter dipole will work on 15, too.  You can feed another with the same feedline on 20 meters with a couple inches separation (more separation is better). 

3) A clothesline antenna...either a dipole, or one of those umbrella types may make a good loop on 10 or 15.

4) An inverted L under the overhang. - begin with the feed at the corner of the house...go up to the soffit, and then run along the under edge of the soffit until you have a total of a 1/4 wave or so.  Feed like a ground mounted vertical, with a couple of radials buried or just on the surface of the grass and let the grass grow over them.

5) and under the facia loop - like the dipole idea, but enclose a whole loop under the facia....

6) on top (of just behind) your privacy fence.  either a dipole,  or a loop around the whole yard if you can go up and over any gateway --- perhaps by building a nice entry arbor or canopy.

I have run a variety of homebrew 80 and 160 meter OCF's for several years that tune most of the bands, in addition to my log periodic.  The important thing to remember is that they are inherently unbalanced, and need both a good 4:1 current balun AND a good coax isolation (either a ferrite isolator, or a multi-tuen coax coil near the feedline, in order to keep common mode RF energy OFF of the feedline and out of the shack.   This may be a larger problem with an attic antenna.

In the attic, I would rather use a balanced dipole than an OCF.  But that is my own preference.

Good luck,

Ken - NM9P

szawrotny

I swear by OCF dipoles. I have three, 2 80-6 and a 160-6. The 80-6's work VERY well with SWRs  below 2:0 on most bands. I do not use a tuner other than the atu on my 6600M. They are easy to build. Use a good 4:1 balun at the top and a 1:1 at the shack. Even better at the top is an rfi choke. I have worked the world (DXCC) with 100 watts.

Bill -VA3WTB

I tried one for a while and found it to be noisy,,not sure why... I went back to my linear loaded 40 and 80m dipole.

N8SDR

Like SZawrotny- I have had very good results with OCF's but like I mentioned they require the correct and a well made balun to work well. If its nosier than you dipole hung in same location its the balun your using, a good well made balun will help negate noise

N8SDR

Yes very stealthy: only two things would concern me if placed in this type of arrangement.

1) Breakage due to high winds, icing or an occasional bird/squirrel incident
2) 26ga wire and high wattage radios or amp and an non tuned antenna with high current /voltage and fizzle like a fuse and your off the air.  

N8SDR

Or make/buy a couple bird houses and build a tall wooden support for them staple the wire on the outside of it, place your ground radials and a 4:1 UNUN under at feed point and your good 6-20 M, Optionally you could use say a metal fence top rail for the support pole and some good PVC tubing and a mount for the base to insulate it from ground and load it up as well,  

Rick - W5FCX

Yeah. Have had one breakage incident in 2 years but in Houston area ice is quite rare (except in our iced tea and occasional libation). The most I have run is 100 watts. Anything more and I get GFCI breakers popping, touch screen lamp ghosts and whistling gun safes. Signal reports are good, too

szawrotny

Why use 26 ga. It has a breaking point of only 25 lbs. 18 ga - 280 , 16 ga 381, 14 ga - 550 lbs. 18 or 16 ga is hard to see.

Rick - W5FCX

It’s stealthy and strong enough. The key requirement in this use case is stealthiness, not strength. The wind load against #26 wire is negligible. It’s field-proven at this point.

Ken - NM9P

You can use a length of mini bungie cord as a stretching strain relief and reduce the risk of breakage, too.

Rick - W5FCX

Interesting idea.  That's why I chose the 8 pound monofilament line as the insulator to bridge from end of #26 wire antenna elements to the fence - it stretches easily and rebounds with quite a bit of elasticity.  A bungee cord might be better except for how visible it is.

The one breakage incident I had was before I started using monofilament. I originally used 30 pound Spiderwire, which has virtually zero elasticity, because it was all I had available at the time.  After the break incident, I switched to the monofilament and no more issues since.

szawrotny

You can string wires around facia and fences around Christmas time without too much suspicion, as long as you add some decorations too. Plan ahead.

Dave - N6XVZ