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eHam Forums => Elmers => Topic started by: EA2COH on June 29, 2004, 11:36:26 AM



Title: Ask for users of Cushcraft MA5B
Post by: EA2COH on June 29, 2004, 11:36:26 AM
I would like to know the useful bandwidth of this antenna in the 20 meters band. Cushcraft says 90 KHz but I have read that some operators have obtained a little more.


Title: Ask for users of Cushcraft MA5B
Post by: KA2UUP on June 29, 2004, 01:25:37 PM
Mine is tuned for the upper side of the band and get a 2:1 SWR from around 14.1 to well past 14.350 MHz, the upper limit of 20 meters.  I plan to lower the center frequency later this summer.  I use a tuner, though.  If you use an outboard tuner the SWR won't matter.  While running 5 watts on 14.082 MHz while I did some tuning for an RTTY program acouple of months ago, I forgot to switch to the dummy load and a station heard me in Alabama.  That is with a SWR of greater than 3:1.

My MA5B is mounted on a Rohn 25 tower at 30 feet.  From experience I can tell you that the antenna is very sensitive to metal objects around it.  I had mine temporarily installed in a pole which put it about 10-12 feet from the rain gutters in my house.  This created havoc with the tuning.

All in all, it is a very good antenna for the price and works as advertised.

Hope this helps!

73 DE Bert @ KA2UUP  


Title: Ask for users of Cushcraft MA5B
Post by: N6AJR on June 29, 2004, 04:39:32 PM
I use auto tuners on mine.  I have had it up for about 8 months and I like it a lot.  

I had it 5 feet over the roof for a while and the metal on the roof edges really messed it up so now it is up 12 feet or so off the roof on a push up pole with guys, ( broken at 9 feet with an insulator) and it is super.

I can tune it with the tuner in the rig or use my at500's to tune it.  it is pretty good on 20 by it self.  I have mine lowest swr at 14.200 and it goes well for about 75 + - either side before I need the tuner.


Title: Ask for users of Cushcraft MA5B
Post by: KR4BD on June 29, 2004, 05:12:44 PM
My MA5B is up about 50' on a Rohn 25G tower.  It easily meets and exceeds the Cushcraft specs for bandwidth.  On 20 meters, I have mine tuned for 1.5 to 1 or less from 14.160-14.270.  With a tuner, the "sky is the limit".  On 17 meters, I am flat across the band.  On 15, mine is 1.5 or better from 21.200-21.450.  On 12 meters, I could only get it to no better than 1.5 to 1 across the entire band and on 10 meters, it is good from about 28.400-28.800 (1.5 or better).  Every installation will be different, but it does seem to work as (or better) than advertised.  I also great great signal reports from DX stations with it.

Tom, KR4BD


Title: Ask for users of Cushcraft MA5B
Post by: N3OP on June 30, 2004, 10:46:36 AM
I have a chart showing Frequency vs. SWR of my MA5B which is mounted at 35 feet. It is located at:

http://www.n3op.com/ma5b-swr-chart.htm.


Reggie
www.n3op.com




Title: Ask for users of Cushcraft MA5B
Post by: EA2COH on June 30, 2004, 02:45:49 AM
Thank you very much to all. This antenna works better than I was thinking
73´s
Juanjo