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A bit of Elmer help needed US Linked Dipole Q, KX3, and Ft-897 Questions


#1

Hey, everyone, I am re-new and honestly, I got my General and then just quit out of Ham. So please brace yourself for really dumb questions. Well, one day I decided I needed to get back into it with a friend. We camp as much as possible so I figured why not tie two hobbies into one. Now we have 3 rigs that will probably be packed up mountainsides. With that said let me get into things. Think technician level knowledge for the most part. I have forgotten am reviewing General again to help my buddy pass his test, and relearn what I have forgotten.

Antennas - I have seen a bunch of linked dipole build pages saved, but they never specify wire exactly, and if it is sourced it is usually in Europe. With that said I am not sure how thick of a wire most recommend. I personally just bought a KX3 so I could drop the mass amount of items involved in the 817, but my friend still wants to pack that 897 up the hill. Would we need two different antennas in case he decides to run a lot more juice via a possible vehicle power supply? My assumption is yes if I want to keep weight down on my end, but I am not sure how much energy we can push. I don’t mind building antennas and think that is fine, but a lot of the sites figure a far greater knowledge of antenna building then I have.

Also, what do I search for in the US for a collapsible pole like the squid poles? I am looking to get the shortest collapsed pole as possible so it will fit the side of my pack.

KX3 - I am looking to bring some power with me for the KX3 with that said I have seen a lot of battery builds on here, but many glances over the regulators people build, or where to even find them. Again I have no problem doing some soldering, and I am very comfortable with LiFe batteries and charging them, but I want to protect my radio.

Ft-897 Same question as the KX3 but with the added interest in what he needs to add such as a good light weight tuner, or should he run a manual tuner to save weight? Also, my KX3 has all the filters but he doesn’t have any. With that said what filters should he get, as we are still sketchy on understanding filters and do to work neither one of us have been able to hit up local hams.

If anyone wants to help two basic idiots who are willing to hike up mountains with radio gear and answer dumb questions that would be great.


#2

Welcome back to radio!

The linked dipoles I’ve made have been of some light weight stranded wire, about 20ga or maybe 22ga. I have a huge roll of some surplus stuff that is silver plated copper stranded and have been using that. Check ebay or wherever for something light. The stuff from SOATbeams is very good tho, if you want some tough stuff. Any of this will handle the power your rigs put out. You lose a bit to resistance, but not significant, for the weight advantage. Be sure to get some small reels to wind up your wire. Kite line spools work well (the plain round plastic ones). I used small sections of 3/8 inch diameter PEX tubing for insulators between sections on my antenna and fluorescent orange paracord for the lines so hikers don’t blunder into them. Go ahead, by a 1000 foot spool of paracord. You know you want to!

For the pole, Amazon is your friend. Jackite makes various length poles. https://www.amazon.com/Jackite-Green-Fiberglass-Pole-Foot/dp/B00B6XWYQS Generally, you want to use a zip tie or something to make a loop for the top antenna attachment and place it at the base of the highest section, not at the tippy-top, which is too flexible to hold the antenna under tension. So you lose about 3 feet from that. I like the 31 footer.

For the FT 897, I’d say the 2.3khz filter for ssb is good. Some people like the tight filter for CW, but I grew up with a pretty broad receiver and rarely use the CW filter. Start with the wider one and see how you do. Not sure about the ATU. You could go with a little Z-match style or just get close with a good linked dipole setup and not worry about an ATU at all.

As for battery, something like this will save you the bother of building anything and will run your rig directly, with no regulators. https://www.ebay.com/itm/BTL14A240C-Lithium-12V-240-CCA-Battery-Tender-Junior-800-022-0199-DL-WH-Combo/222702480205 If you’ve never handled one of these they are insanely light weight, almost as if they were an empty plastic shell. Make some provision to protect the exposed terminals in your pack.

Just my 2 cents worth here. Hope it helps!

73 - Bruce WB8OGK


#3

A LiFe 4C battery with a terminal voltage of 13.2 volts will be quite suitable for your KX3 and does not need a regulator even when the battery is fully charged.

I have a 4,200mA Zippy brand for my KX3 and this has enough grunt to do two activations with ease at tx power levels 5 to 10 watts o/p.
Unbelievably light, the battery, KX3 and other odds and sods easily fit into a lunchbox for protection.

A Turnigy ACCUCELL 6 charger is excellent with a wide range of different charging voltages and currents to suit just about any battery in existence.
Quite a number of VK activators have this charger as it is so flexible.
Bought all my batteries and chargers etc from HobbyKing.

Good luck with your activations and campouts. Cheers


#4

Bruce,
I second your recommendations!

Though I do not use linked dipoles, my 300 ohm ladder line dipoles are pretty light with short feedline and #22 wire (.644mm European, and #18 is just barely over 1mm). They have handled 5 to 100 watts with no problems. As an FT897 user fully agree on filters and resonant antennas are always more efficient than non. As to batteries, call me a luddite because I still use AGM.


#5

Just remind him that any type of connection to vehicle is not valid for a SOTA activation.


#6

Yep we know but I was more concerned with it for thugs like field day. Trying to keep the antenna field to a the best minimum for now. Appreciate the reminder though, all are sota will be camping I’m sure.


#7

Are they single band affairs?


#8

Welcome aboard Mark & friend.

There’s a huge amount of information on here Mark. Discussions about antenna types and their performance. Likewise radios, batteries, keys and paddles, poles, wire etc. Use the magnifying glass icon in the top right of the screen to access the search functions. You’ll be able to lose yourself for hundreds of hours reading what’s been said in the past.

For your KX3, as already said, a LiFePo battery and Turnigy charger from Hobbyking is the simplest solution. There are many other battery and charger brands and vendors, but Hobbyking is a good place to start.

The 897 is not a radio I’d want to take up a hill unless you are going to carry it for me! Nothing wrong with it, essentially an FT817 with extras and a 100W PA. But it weighs just under 4kgs which is 4x what an 817 weighs and 817’s are not light compared to many other radios. If it’s all that that is available then it will have to do. But really it belongs back at the campsite. If you want to run it at more than 10W for any length of time, you’ll need some large batteries and it (along with the 857) likes a good 12.5+ V to operate. The 817 will run down on 10V happily.

For antennas there is no right answer. Every antenna has advantages and disadvantages. Resonant antennas need no tuner and so save weight at the expense of limiting you to the bands the antenna works on. A tuner gives you more bands for more weight. If there’s one built in your KX3 already then there is no issue, you’ll be taking one with you.

For QRP and low power use, you can use very light guage wire. My antennas use wire I bought at a hamfest a while back, I got several hundred metres for a few pounds. It’s 1.2mm PVC multistrand (0.05in) in grey. Yellow is a much better colour, it stands out against rocks, soils, green vegation and brown vegetation. I have grey because that’s what was on sale. I use RG-174 coax for feeder.

To start with, if you have limited construction experience, I would make some link dipoles. They are the easiest to build with limited test equipment. There’s a design on here by GW4BVE that you can build using the dimensions given and it will work, no trimming needed. I’m assuming you are both SSB only operators at present and we are approaching the sun-spot minimum, so the high bands 15/12/10m are open not too often. A 40/20/17m link dipole would be an easy starting point. When (if) the sun wakes up you can extend it to offer 15/12 & 10m.

Once you have used that and got back into radio and operating etc. you can look at making vertical and end-feds. You can make and expeirment with wire antennas for almost no cost and it’s fun (IMHO) finding designs that work well as antennas but can be deployed easily on a mountain when you have strong wind and it’s cold. There are more antenna ideas to play with than you can imagine. You’ll find one that best fits your needs and the kind of summits you operate from.

Finally, the bit nobody has told you yet. Not only will you get to enjoy going out camping in the countryside, not only will you get to enjoy climbing up the mountains, but when you start operating from the summit, you are the DX and people chase you for the contacts rather than you have to try to break the pile up on some other station.

The other bit nobody has told you, this aspect of amateur radio becomes very addictive very quickly.


#9

Yes, wound a 49:1 balun and now have radiators cut for 20 and 15 meters.


#10

You can use any wire down to #28 for ten watts. I use #26 and #28 teflon insulated wire so that I can run it over branches with impunity. 73, Fred KT5X (aka WS0TA)