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Reviews For: Radio Works OCFD MAX

Category: Antennas: HF: Verticals; Wire; Loop

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Review Summary For : Radio Works OCFD MAX
Reviews: 2MSRP: 80.00
Description:
The Off-Center-Fed Dipole that works! With Special Matching Unit optimized for off-center-fed antennas. 80, 40, 20, 17, 15*, 12, and 10 meter coverage in 132 feet. * 15 meter coverage requires the 15 meter add-on kit.

Product is not in production
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# last 180 days Avg. Rating last 180 days Total reviews Avg. overall rating
0023.5
WV4I Rating: 2011-07-07
needs a tuner-at least Time Owned: 0 to 3 months.
I purchased this antenna with the 15M add on (free) with the intent of working 80-10M up to legal limit power. Otherwise I would have simply kept up my DX-LB Plus, which worked/tuned as advertised, same height, coax length, apex angle, etc..

Despite many iterations of positioning, changing 15M element angle to main elements, etc., I never saw an SWR dip any closer than 20.3Mhz to the 15M band. And 20M was always above 3.0:1 thruout this process. 3.5 and 7 mhz did have good nulls near the bottom of each band. 10M had an observable dip approx 29.5Mhz. 6M at 50.2Mhz.

The problem with overcoming these high SWRs with a tuner is that the balun will likely get fried eventually, especially at higher power levels.

For fun, nothing to lose, tried re-cutting this antenna to 40M, i.e. 23' and 45' legs. No help on 20M, 40M still looked okay with 2:1, and surprisingly now had a very good match on 12M. 15/17M forget it. 27.5Mhz about 3:1.

Last, tried removing 15M legs. No change 40M, now 20M 2:1, and rest of bands it's (still) tuner time. 12M now flat with high SWR.

For 100W, I use an LDG AT200Pro which is rated at 6 to 1000 ohms HF, with 6M 16 to 150 ohms, and it will get a match on every band 80-10M.

For QRO, I use an ATR-30, which is rated at 35-500 ohms legal limit plus, far more at lower power. Guess the antenna will either survive QRO on the higher SWR bands or I'll start seeing snap crackle pop.

Takeaway? Perhaps make two of these, install at right angles. Say, one for lower bands, and one for higher, with different value baluns. Don't know. But I doubt this antenna will survive QRO, if even 100W.

Don't know if the Buckmaster is better/different performing, but at least they do publish the charts/theory if you want to read more.

DX Engineering has a large assortment of baluns of various ratios, if you choose to make an OCF dipole yourself.
WB4RTP Rating: 2011-06-26
Well made, works great! Time Owned: 0 to 3 months.
I bought the OCFD MAX+15 version with the optional 15-meter kit already installed. It was very neatly packaged with numerous cable ties to keep it from tangling. Directions were concise and clear, but except for the tie lines for the 15-meter kit, there wasn't much to do except attach feedline and end ropes and hoist it into the air. I installed it at my club's Field Day site about 30 feet in the air with 100 feet of RG-8X feedline. On 10-meters, I was making about 60 contacts per hour when the band was open, then went to 15-meters and did almost as good. After dark, it worked great on 80-meters. I had many complements on my good signal. SWR on all of these bands was typically between 2 and 3, so the internal antenna tuner on the TS-2000 I used had no problem making a good match. It was constructed out of parts that are individually for sale at The Radio Works, and they are all good quality. Now I just need to figure out how to put it up on my small city lot.