MFJ 16010 RANDOM WIRE TUNER?

[KD6WAG]

I'm thinking about buying this nice and small random wire tuner. I've already read some reviews on eham.net but they are pretty old. I'm wondering what some qrz.com users think of that tuner.

I want to use it for field use and I like the compactness. I already have an LDG 200Pro, but I want the random wire tuner to be able to go "light and portable" with ease.

Thanx.

[NN4RH]

I have one. I bought it about four years ago. I think I used it maybe three times.

Nothing wrong with it. It's just that after awhile it made more sense to me if I wanted to go minimalist portable, to just bring resonant antennas or tunable antennas, and leave the tuner at home. So, I have made up several W5ALT Travel Antenna (http://www.comportco.com/~w5alt/antennas/index.php?pg=4) for 20, 15 and 10 m when I need to travel light. And I have a Superantenna MP-1 (http://www.superantennas.com/html/mp-1_portable.html) when I can bring a little more with me. THere are other similar base-loaded portable antennas, or you can build one yourself e.g. W5ALT Indoor Vertical Antenna (http://www.comportco.com/~w5alt/antennas/index.php?pg=3). #The point is that if you have an antenna that is close enough to resonance to give 2:1 or better, or can be adjusted, you don't need the tuner.

Having said that, if you're still interested in getting a MFJ 16010, I'll let you have my almost-unused 16010 relatively cheap. Email me.

[K5RCD]

As a random wire tuner it works very well. I have used one at 100 watts in my travel trailer a few times, and with a long enough wire it will tune down to 160 meters.

Max wattage rating is 200 watts, and I imagine it can handle that nicely.

I now use mine only as a tuner for a short random wire to a receiver in my shack. Works for that too.

Incidentally that tuner is still in production and was the first product MFJ ever marketed.

I think it will serve your intended purpose as well as anything available, and at a reasonable cost. #http://www.qrz.com/iB_html/non-cgi/emoticons/cool.gif

[KD6WAG]

Do you guys use a balun when your running a piece of random wire?

Here is what I was thinking of using. By the way, my wife bought me the radom wire tuner for Christmas.

Taking a long piece of wire without measuring it. Basically, keeping it "random" in length. Throwing it up into the top of a tree for the "hot" wire side of a 4:1 balun. Then running a smaller wire to the ground terminal of the balun and laying on the ground or driving it into the ground with a stake.

Next, connecting some RG-8 coax (about 25' length) to my random wire tuner and a 1' coax out to the radio.

Will this work? Thank you.

[NN4RH]

Quote[/b] (KD6WAG @ Jan. 07 2008,00:14)]Do you guys use a balun when your running a piece #of random wire?
If your antenna/counterpoise is connected directly to the coax, you should have a so-called "choke balun" or "current balun" at that point; i.e. about 10 feet of of the coax wound about 7 turns side-by-side. This should reduce the common-mode RF current on the coax shield that would otherwise end up in your shack. #If I wanted to nit-pic, this really isn't a "balun" but that's what everyone calls it.

Quote[/b] ]Taking a long piece of wire without measuring it. #Basically, keeping it "random" in length. #Throwing it up into the top of a tree for the "hot" wire side of a 4:1 balun. #Then running a smaller wire to the ground terminal of the balun and laying on the ground or driving it into the ground with a stake. #

Yes. The random length antenna needs a counterpoise or ground to work against. Just laying it on the ground would be fine, or use something like a landscaping stake to hold it in place, but you don't need a ground rod

Quote[/b] ]Next, connecting some RG-8 coax (about 25' length) to my random wire tuner and a 1' coax out to the radio.

Here's where you get into some trouble if you're going to transmit with this arrangement. That random wire & it's ground/counterpoise is probably not going to match the coax - the SWR will be quite high at some frequencies. Let's say 50:1 or more as an example. You've got 25 feet of coax plus #another 10 feet for your "choke balun". If you look up what the loss of 35 feet of coax is at SWR of 50:1 at say 14 MHz, you're looking at 5 dB of loss (100 Watts in, 30 watts out). Plus the voltages at the feed point could be quite high at some frequencies. #

If you tailor the lengths of the antenna/counterpoise you can design such a system to minimize the SWR on at least one band of interest. But doing so is automatically going to give you a worst-case on some other bands.

These tuners are really intended to directly feed the random wire; i.e. attach the wire and it's ground/counterpoinse directly to the tuner. If you have to use a coax from the tuner to the antenna, make it as short as possible.

[aj8l]

I have one mounted to the outside of my backpack that contains an SG-2020. I connect a 40 foot piece of wire to the tuner with a bannana plug and throw the other end of the wire in a tree. The tuner is connected to the radio with 1 foot of coax. I tune it easily on 20 through 10 and have even had luck tuning it on 40. I do not use any counterpoise. Stay away from 1/2 wave length wires with respect to the band you want to work. The impedence will be too high for the tuner. An antenna anilyzer helps in tuning your wire. Geoff, AJ8L.