Hello everyone, haven't been here for a while. My question is.... I have an Arrow 4 element beam for 2 meters. It is rated at 150 watts, Do you think I would hurt anything if I ran 300 watts thru it ? :cool2:
Hello everyone, haven't been here for a while. My question is.... I have an Arrow 4 element beam for 2 meters. It is rated at 150 watts, Do you think I would hurt anything if I ran 300 watts thru it ? :cool2:
Depends on several factors and the most likely scenario is breakdown of insulation at a high impedance point inside the antenna somewhere.Originally Posted by kk4fpx
First, did the manufacturer rate it conservatively? (an unknown, most likely). Second, what kind of modulation and duty cycle would you be using? Third, depends on how well tuned it is. Higher VSWR will increase the chances of something flashing over. Fourth, depends a little on your elevation and relative humidity. and fifth, why would you want to? You're not going to gain a whole lot in the grand scheme of things.
I'm using a TM-281 Kenwood at low power ( 25 watts ) into a Mirage amp. I bought the amp at an auction for $45.00 mainly for the preamp to work birds with. My elevation is around 4000 feet above sea level and the humidity is high. I check into a simplex net on Sunday nights that's about 60 miles away, thought the amp might get thru better. I originally had a 5 watt ht on it but needed the ht for uhf.
Ah, understood. Can you lower the output of the Kenwood at all? If not, you might want to look into building an attenuator to decrease the drive into the amp. It would need some hefty resistors, but very doable. A lot of AM radio stations with older transmitters that couldn't do very low power, use resistors to burn off extra power as heat, to decrease the power to the antenna to meet licensed levels for lower nighttime power. Let me see if I can dig up some formulas for you on that, if you're interested.
Kenwood is not adjustable High and Low that's all. I noticed several of the Arrow antenna's were rated at 150 watts , so that might just be a ballpark figure.
Arrow antennas are well built, but I wouldn't do it.
Which Mirage amplifier? The 300 watt B-5030 G I'm familiar with does 300 watts with 50 watts drive.
25 watts drive would be less output, and probably OK.
Do you have a watt meter for 2 meters and a dummy load or antenna that can take 300 watts?
Measure what you actually are putting out.
"Where would we be without the agitators of the world to attach the electrodes
of knowledge to the nipples of ignorance?" ~ Professor "Dick" Soloman
Exceeding the power rating on an antenna by 100% is a sure-fire way to destroy it. I'd go with "don't do it" as well.
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Aw, don't listen to these scaredy-cat old farts—that 150 watt limit is just a scam to trick you into buying Arrow's more expensive antennas. Go ahead and run a kilowatt through the thing, it'll be fine. A little arcing never hurt anyone. Well, not much, anyhow although it's burned down a few houses, maybe...
Waiting...waiting....waiting; isn't anyone going to tell him that doubling his input power equals a 3 dB increase to the antenna and, that the 3 dB increase in his signal would *probably* not make a difference on the receiving end.
Maybe I'm wrong about that, maybe 3 dB gain would make a difference EME or Sat-Comms, feel free to edify me.
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ETA: Doubling you watts is not the same as doubling the length of your pecker; hard to get that concept over to the CB crowd!
Last edited by koØm; 03-24-2015 at 08:19 PM.
The Mirage is the B 3030 G. It's not listed on their site. It says 30 in 300 out. I was getting almost 100 out with a 5 watt ht and I'm getting 300 out with 25 in, measured with two different meters into a home made Egg beater antenna.
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