10 Meter Dipole and learning

I had put up my 10 meter dipole when I set up my ICOM 740, and had it at 16.5′. I had used a way out of the house for the feedline that had me using a lot of coax. I had trouble with SWR, I could tune it out but I was not very efficient. I found another way to get my coax out to my antenna and it knocked off about 45′ of the feedline, yes 45 feet. I was able to raise the top of the dipole to 21.5′ and now now roughly 12′ to bottom of mast of feedline. I still have a little off balance inverted V with the higher side pointing west, but only a few degrees different than east side.

Right off the bat I found 1:1.2 swr on my radio without tuner and this was at about 65% of RF power. Very little done on antenna tuner now to get it at 1:1 and if I go full power I can still tune it down perfectly. Next week I will be building my 50 ohm dummy load, just waiting on some resistors and need to go out and get my paint can and some mineral oil.

I found a good deal on both the General and Extra ARRL books so I have been reading those. I have been reading one section in the General book and then part2 so to speak in the Extra book. I am starting to pass the practice test for general, still marginal but I am passing about 60% of the time. Another week or two and I will raise that average.

I have quite a few projects on deck:

  • Found some really nice surround speakers plus center speaker at Goodwill, Sony’s want to use them as externals for my HF rig.
  • Have a LM386 Audio chip I am thinking of building into a mono amp to feed the Sony speakers, maybe build a small Eq tone stack to use as listening filters.
  • Parts arriving for my homebuilt bench power supply will be here in a few days and time to get that project in a box.
  • Have some 300ohm twin lead and some really old plans for a doublet dipole fed with coax and an air choke.
  • Arduino parts arriving late in week and ready to start on my weather station project among others.

Until next time…

-KG7FDJ


2 Meter Vertical Dipole with air choke

After gaining a few pieces of equipment at the hamfest I was eager to see about getting a more efficient setup on 2 meters. New amp and i had just finished reading “US Army RADIO WAVE PROPAGATION AND ANTENNAS” on my smartphone So I looked around the net for possible ideas and with what I had on hand I arrived at making a vertical dipole.

I started off with making a air choke in hopes of eliminating some of the static I get on 2meters.

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I had a Monster, project box and a pill bottle, time to get busy.

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I slotted the end of the box so I could slide in my l brackets I was going to use to bolt the copper tube to.

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Used some stiff plastic as a stiffener and isolator

My pill bottle was about 1.5″ and I put on 6 winds of RG58U

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All mounted in box, I mounted a pvc fitting to bottom so I could mount on my mast so the coax fed the center at a 90 degree angle. I will post pics of it mounted outside soon. The 7/8 copper pipe  kinda test the pvc and my heavy fishing line guy lines.

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It tuned in 1.3:1 on 5 watts and a bit higher when i turn the amp on. I can hit many more repeaters and certainly hear a lot more. I forgot to mention I raised the antenna to 16′ in the air where my old one was only at 10′. I still have this annoying pulsing  static that I hear when listening to a few repeaters, I am still trying to pin down the cause of this.

-KG7FDJ


Slow Update

Well It’s been busy, or I have.

Last time I was here I was heading to our local hamfest the next day. We went, my friend and I and we made our way around the tables. Plenty of old boat anchors holding the tables down, cardboard boxes of cables and odd devices. I like thrift stores and yard sales for finding that hidden gem and here it is a concentration of used goodies but you dont have to wade through paintings of tigers, baby clothes and other fashion violations to find the gem.

BUT….

Most of the stuff even at a hamfest In reality and even though glazed over geek-electronic eyes is still mostly junk. Or, maybe not. I get a certain type of marketing anxiety when I look at used goods, piles, boxes and items that are not self explanatory. I see the guy with the box of odd items and I can identify a few, theres a balun, a matching network but what is that other item? Is it a vhf linear amp, a transverter of some sort? It is a big aluminum heatsinked box with a price tag of $35 on it. I can bet these guys would be loading up a lot less to take home at the end of the day if they organized their items. Few 3×5 cards to tell you what it is. Unpack the stuff and put those oil stained cardboard boxes you took from the shelves in your garage and put them under the table. Can you tell I have been a exhibitor/vendor at a few trade shows in my life? All I can say is why bring the stuff if you don’t actively sell it? Even the most introverted can get a sharpie and some 3×5 cards together the night before.

So back to what I found…

I was looking for a tuner and possibly an amp for my 2meter HT to use out of my house. I found this SST T-4 Ultra Tuner for $10, I took it thinking I found half of my solution.

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In very good condition, no box or manual. I have not yet been able to find a manual online but the operation is pretty straight forward. I did find a couple other models on ebay made by SST and found another interesting bit of info on SST:

“SST tuners and SST records were basically the same company, Black Flag( the LA punk band) founder and guitarist Greg Ginn was a ham radio buff and electronics builder before he picked up a guitar and became a early 80′s punk rock icon. Solid State Tuners basically morphed into SST records when vinyl records of his band ended up out selling his radio electronics and he gave music a full time career run. Good luck finding old SST electronics cheap…..Black Flag fans have been snatching them up and even having Greg Ginn autograph them.” This was from KB6NU’s page HERE

I kept walking around the tables and spotted on top of its original box a MFJ-941D that the guy was asking $45 for. I hit my smartphone ebay app and found they were going for a bit more there I offered him $40 and he took it. I have read about this series of tuners and seems like guys  are all pretty happy. My intention was to get one of MFJ’s newer models but this was a score in my opinion, complete with manual.

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I figured I could always turn the SSST tuner I just picked up for more than $10 or keep as a backup since it was only $10. The tuner has been a big improvement even right off before I cleaned up my antenna feed(more on that later).  I am currently waiting on a box of resistors to arrive so I can build a appropriate dummy load for my setup.

I walked around some more scouting a key and a vhf amp or mobile radio with a little more power. I found a few but pretty beat up and little proud of from the price they were asking. I came upon a guy with a TPL 70watt 2meter/vhf/FM/SSB linear amp for $25 and I walked away with it for $20

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You can also see a Workman CX-3 antenna switch. If you ever get a chance to buy one of these, DONT. unless of course you like brittle cold solder joints, and a slightly bent rotary switch shaft. They cost about $12 and if you look at like you are just buying the hardware and it is a kit you must re-solder then it’s not a bad deal. For those that think just buying one and hooking it up should be aware to open it up and heat up some joints.

I came away with a couple adapters and small coax patch cables, all in all a good haul.

-KG7FDJ


I Like Blue

I didn’t really like the yellowish backlight on my VHF/UHF SWR Meter so I opened it up and grabbed a blue LED to replace it with. I added a small toggle switch as well so I can power the backlight off without having to unplug the power from the back.

It had 12volts already coming in from a power supply so I had to find the right resistor to use on the LED. It is a basic formula:

To calculate the resistor needed for a simple LED circuit, simply take the voltage drop away from the source voltage then use Ohm’s Law.

  • Es is the source voltage, measured in volts (V)
  • Eled is the voltage drop across the LED, measured in volts (V)
  • Iled is the current through the LED, measured in Amperes (Amps/A)
  • R is the resistance, measured in Ohms (Ω)

so..  R=(Es – Eled) / iled

If you don’t want to bother with that you can go HERE

I needed a 560 Ohm resistor to make my LED work on 12volts

I just like the blue backlight!

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Wish I had a little smaller switch to use but it gets the job done.

-KG7FDJ


HAMFEST TOMORROW!

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I am hoping to find a decent deal on an Antenna Tuner there and other goodies! Be nice to win that raffle as well but it will all be fun going to my first Hamfest.

-KG7FDJ


Arduino!!!!!!!!!

Well I got a gift in the mail from my Father-in-law an Arduino Starter kit!

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Uno board, USB cable, Parts, book and a breadboard!!

I downloaded the IDE and started building and getting familiar with the c code.

Built through the book fast doing the basic projects that teach you the fundamentals and coding structure.

Digital Hour Glass:

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Talking to the LCD display with the code:

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One book is definitely on my list to buy “Ham Radio for Arduino and PICAXE”

I am addicted already, what a great little platform for electronic experiments. The internet is full of projects and resources More on Arduino later.

-KG7FDJ


HF Radios

Looking around for a decent High Frequency Multiband transceiver isn’t an easy task if you are new to amatuer radio and a frugal shopper. I watched Craigslist and Ebay for a couple weeks before narrowing my options down.

I learned a few things along the way as well. One of the first radios I found was local on Craigslist and the add said it had 11 meters on it. I looked up the model a Yaesu FT-101E. According to the specs it had ability to listen to 11 meters but needed to be modified in order to transmit on 11meters. Now for those who don’t know 11meter is the CB radio band. Not a HAM band and what I learned in reading about radios that had been modified is that they are not FCC legal. This is an old tube radio and for some reason my romance with old radios of my youth drew me in to look at older radios first. Not the best idea. I emailed the guy and we talked back and forth until I asked if the 11meter mod had been installed to make it transmit, in this email I had happened to change my signature to include my callsign. No reply.

I wondered if my question and callsign made the communication stop. As I type this the radio is still listed on Craigslist for sale.

There are horror stories out there of so called modded radios that look like the work of a 3 year old with a soldering iron. I had to ask myself why I wanted an older radio like this, all tubes, no frequency counter, more likely to need work now or in the future. I am sure there are plenty of “boat anchors” making QSO’s daily but not the best idea for a guy starting out.

It appeared to me the best options for me based on reliability, ease of use(learning curve) and mostly price the 80-90’s solid state stuff was what I should be looking at. I checked out Kenwoods, Icoms etc. I had narrowed down to a couple on Ebay.  Had to look careful and really read descriptions so many “work great except on 40 and 80 meters”  Or ads that say “tested” but as you read on tested means they put power to it and the meter lights lit up.

Well to cut to the chase I found an ICOM IC-740 for a good price and took it.  It has the optional power supply in it, the FM, all the filters for cw and passband. even came with the stock Mic.

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I picked up a 10meter Dipole from DR.Dipole as well.

I set it all up, put the center of my dipole 17.5′ in the air as an inverted V. Got inside and my swr was over 3:1 according to the radio. Whoa! this is no good, I am suspicious of my long run of RG58 making things whacky. I rolled the power back and was able to keep it around 2:1 at 45watts. I ran up to Radioshack the next day and grabbed their SWR meter to see how close it was to one on radio. It was fairly close so I called out on 28.400 and listened. Now I know it is a terrible time of year for 10 and 12meters but a guy has to try. I tuned and listened on 40/80 and 160 meters was able to pull in a few to listen to. Heard a lot of cw on 20 and 40 meters. But no QSO’s for me. I can see right off the need to learn morse code again.

I have not had a chance yet get the dipole down and do some trimming or repositioning, I have been looking at antenna tuners and I want my dipole as close as possible without a tuner but I can see life will go a lot more easy with one. I happen to get the MFJ catalog recently and I like a few of their tuners.

I have been reading up on Baluns and the use with tuners, not totally sure if I am going down the right road trying to use a tuner as opposed to directing my attention at the physical antenna. It is 10meter 1/2 wave Dipole and after measuring it seems as if it should work just fine. So I will be trying a different feedline f coax to see if it helps but I still want to get a tuner if not for this situation but for other antennas and the other bands.

-KG7FDJ


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