Posts Tagged ‘Portable’

End Fed Tuner Success… sort of

Had a good day in the park with Jim K4AHO and Wally KG4LAL. Spent a good bit of time testing a couple tuners for End Fed Half Wave antennas using Jim’s AIM 4170. Wow is that thing a great tool for tweaking antennas! Info overload!

I built an antenna tuner based on AA5TB’s design for an end fed half wave antenna. I am using a 3 ft or so counterpoise on the ground as Steve suggests. On the analyzer in a test lashup it was a bit touchy to hand capacitance but tuned well even up to 21Mhz. Since I am not thinking of backpack size I used a pretty good sized enclosure for it. I am using an air variable 6-160pf cap instead of a polyvaricon like Steve used since space is not a big issue. I also used a T68-6 toroid instead of the T50-2 Steve used.

Test lashup of EFHW TunerWhen I mounted it in a plastic box the sensitivity seemed to increase. I have not put a LED SWR bridge in the box yet, as I was waiting to see how it worked before adding more variables. Today I was able to put an AIM 4170 analyzer on it and it did tune the antenna… seems that the air variable I used is perhaps a tad small. It is almost fully meshed on 40m cw and on 20m it acts like even at minimum capacitance the sweet spot is very narrow and hard to tune.

In the box details

Here's the innards

My question(s) are:
1) Is the hand/body capacitance normal? If not, what might cause it to
be so touchy?
2) Would my parts layout be part of the issue?
3) Does the DPDT switch (mini toggle) I added for later use with the SWR
bridge add significant capacitance to the circuit? I was able to match a
21Mhz load on the raw test setup, but not once it is in the box.
4) I have a small bus wire for a ground, do I need to increase that?
5) Is the plastic box the problem? Would it be better in a metal enclosure?
6) Am I asking too many questions? Sorry, this is how I learn. Build,
test, ask… :-)

The SWR Bridge I want to use

SWR bridge I want to use

Thanks for your wisdom and experience on this one.

72,
Kelly K4UPG

NEScaf Filter Saves the Day

As one of the many antenna restricted condo owners of America, I cannot operate as often as I’d like. The hassle of putting up and taking down temporary antennas wastes time, isn’t always practical and generally spoils the fun for us.

Great that we have some holidays and time off as it allows a bit more opportunity to get on the air. The MI QRP group hosted a 4th of July Sprint and although the hour was late (7-11PM EDT) since I did not have to go to work Monday, I took advantage of the chance to work a few of my fellow QRP ops.

Rain and lightning welcomed my efforts to set up an antenna. So I forsook my normal setup and settled for a twinlead 44 foot doublet hung from my 20 foot Jackite pole which was bungee cord strapped to a ladder in the back yard of our condo. The antenna ran north south so much less than ideal, but at least I could get on the air.

NEScaf Filter

Freshly Built NEScaf saved my bacon!

The day was saved by my freshly built NEScaf filter. As one of the lucky ones, I recently received the latest edition of this great kit provided by the NE QRP bunch. It enabled me to listen to cw despite the high QRN and background hash from neighbor’s TV’s, computers and air conditioners. What a joy it is to actually hear stations through the noise. This is a must have accessory for the condo based QRP op! I am still learning to use it well, but am mega-impressed with the capabilities it offers. With this audio filter, I could null out the QRN and peak the CW signals making for much more relaxed and enjoyable copy. The extra audio boost helps my little Sierra audio too. Keep watching for the next round of kits!

Polar Bear Summer Picnic Event Jun 2010

My favorite QRP group is the Polar Bear QRP gang! We have a good time and enjoy outdoors activities and trying to connect with one another at least once a month with some kind of activity. To escape some of the heat, I got an early start on the day. I wanted to try out a new mini-bac antenna configuration and knew it would take some time to get it up into the trees. BOY WAS THAT AN UNDERSTATEMENT! It was 110 ft doublet with a 40 ft feedline that was setup as a ladder line. Not an easy one to get up single-handed. Thanks to some tall trees, was able to get it up about 40-45 feet in the pine trees. It loaded great on 40m, but was disappointing on 20m so I ended up setting up my W3EDP in an L from my 20 ft Jackite pole to a nearby cedar tree at about 35 feet.  The sun chased me into the treeline where I settled in to chase bears.

Abandoned mini-back doublet feedline hangs in foreground

My xyl Connie took a picture that shows the mini-back feedline hanging in the breeze after I shifted positions and setup the W3EDP in the shade. Grrrrr!

Osprey perched right above my head…cell phone picture

Was able to work a couple of the Polar Bears, Mike W3MC in MD and Guy N7UN up in the mountains on a trail(?) in NJ. I heard VA2SG but he was at ESP level briefly then faded away. I did hear a few others working him though. WA8REI was working Guy but I could not hear him at all and ended up tail ending their QSO to connect with N7UN.

Got to work a few others through the QSB and poor signal strength on 20m including Pastor Les, K4NK in SC, KE5SBZ, Ed in TX, N1FJ in MA, and Phil W3HZZ in Atlanta so it was a nice way to spend a few hours outdoors in the heat.

Connie brought me a picnic lunch and we enjoyed the osprey and bald eagle show as they fished Lake Fredrica.

Had to drink extra coffee to copy speedy W3MC's signal

This is the life… outdoors and ham radio…making QSO's…PTL!

K4UPG Back in Action!

Many work responsibilities have kept me off the air more than I’d like lately.

But we did manage to break away for a few days with family in Tennessee over Memorial Day. It was great to have an opportunity to get together with Chuck, AF4O the Hillybilly Bear and fellow Polar Bear QRP group member. We had an opportunity to work a bit of QRP portable in the Chickasaw State Forest in West Tennessee. It is a very natural and beautiful location and Chuck took me to his special spot in a very old and interesting cemetary set deep in the very tall hickory tree forest. Wow! I believe the latest date on the grave markers was 1927 and there were many from the early and mid 1800′s. It is a lovely and isolated spot.

K4UPG running a 30m EFHW sloper from the edge of the forest cemetary

Chuck said to bring along a screen shelter and I sure was glad I did! This was also a great spot for deer flies, hornets and other interesting biting bugs!

He had a nice setup and was running a random wire on 20m which he launched by throwing an antique glass insulator from an old telephone pole over a tree branch. He has a better arm than I do… think that heavy insulator would have broken my arm!

Back at the in-laws home in Jackson, I had some time to operate deck portable and was ably assisted by my niece Chloe. Conditions were horrible, but it was fun to be outside and hearing some sweet dits and dahs for a bit.

Now I am gearing up for the next outing of the Central Florida QRP group. The weather is HOT and the summer thunderstorms are back, but life and radio must go on… cu on the air!

72,

K4UPG

AF40 downs a Mountain Dew and doesn't miss a character of CW

Chloe gives me advice on copying cw through the QRN

QRP TTF 2010 * Disappointed in Orlando!

On the road again… happy feet dance! K4UPG is loaded and ready for a good day by the lake operating the QRP To The Field event for 2010.

Packed up and ready to roll

K4UPG ready to roll to QRP TTF site

Kitchen Sink Approach

Loaded with ALL the options!

Then came the wind knots in the antenna launching rig! I wanted to get a doublet up as high as possible. Took nearly 2 hours to get my antennas up in the air. LESSON LEARNED: It is really helpful to have another person along to help untangle all the knots that wire and string seem to make all by themselves.  Getting  the antenna up quickly is a key to portable ops. Grrrrr!

Wind knot

One of several tangled messes that delayed the antenna deployment

LESSON TWO: After a delayed start, I spent a lot of time moving my portable table to keep out of the direct sun! With temperatures in the upper 80′s it was HOT and direct sun causes my Sierra to drift a bit which makes qso’s more difficult. Need to get a sun shade setup and not waste time moving my position.

The band conditions were pretty poor and I did not hear as many stations as I had hoped. The ones I did work were tough going and seemed like others could not hear me responding to their CQ’s.  I didn’t even hear a lot of Florida QSO party ops, but sounds like others that were farther away did. In 5 hrs I managed three whole qso’s with TTF stations. I did hear one Polar Bear– Martin operating as VA3OVQ but he could not hear me when I replied to his CQ.

Don't fee the Gator!

Warning sign about 30 feet from my operating site!

It was fun to be outdoors and playing radio! I did not get eaten by our neighborhood gator either! Maybe next time out will be better contact-wise.

Hontoon Island Qualification Report

Great weather, great site, and despite so-so band conditions but we made over 25 contacts to be able to submit our qualification of Hontoon Island, Deland, Florida as an official island to be listed and activated as a US Island On the Air.

The main picnic site

The main picnic area near the ferry landing

The team consisted of Wally Crew, KG4LAL, Jim Diggs, K4AHO and Kelly, K4UPG. We used the special event callsign K4T on operated on 20m cw and ssb, 30m cw and a few unsuccessful attempts at 40m & 15m cw. Jim was our secret weapon on 20m with his good cw, K-1 and a Par End Fed antenna in vertical configuration on a 33 ft MFJ telescoping mast. Without his contribution we would not have been successful! So a big thank you Jim for your good operating skills and equipment that made it happen in less than 8 hours at QRP levels.

FL481 is ready for future activations!

Thanks to the Polar Bear QRP group, QRP-L members, 4 States QRP Group, GORC QRP Spots, US Islands organization and HF Packers that helped out by listening and attempting to connect with our effort on Hontoon Island. It was fun to work as a team!

Tallentire Hill

By the time I had finished repairing the TH-205E the sky had cleared and the sun had come out so after tea I thought I should go for a bit of fresh air and exercise. Olga is still suffering from a chesty cough and didn’t want to come so I decided to drive over to Tallentire village and walk to the top of Tallentire Hill. A couple of weeks ago I had spent a couple of hours parked near the top making some contacts from my HF mobile station. But it isn’t possible to get right to the top by car unless you have a 4 wheel drive vehicle, because the track is rather stony. Even if you had a 4×4, there is nowhere to park off the road right at the top. The actual summit is in a small field and accessible through an unlocked gate from the track, but it is presumably private land so whilst walkers enjoying the view may be welcome, hams setting up a portable station would probably be accused of trespassing.

But on a day like today it is worth going just for the view. The picture above shows the trigonometrical point (a reference point for measuring height used by the Ordnance Survey) looking south east towards the Skiddaw range. On the larger version (click on the small one to see it) you can see snow-covered mountains beyond Keswick in the background.

The next picture shows the view south west and on the large version you can see some of the buildings of Cockermouth nestling in its valley. The big mountain on the left is Grasmoor with its steep drop towards Crummock Water. In the distance you can see the Buttermere fells.

The last picture shows the view north across the Solway to Dumfries and Galloway in Scotland. I don’t know the names of the Scottish mountains.

I would love to own the field containing this summit so I could use it as a portable site whenever I wanted, even if it meant buying a 4×4 vehicle! With the take-offs shown in the pictures the site might be quite good for VHF, so I will have to take the MFD and the FT-817 up there one day when there is a 2m contest in progress.

Today I didn’t manage to raise anyone with the TH-F7E I took with me. But despite the sun it was pretty cold up there with a stiff breeze so after a few calls on 145.500 I headed back down again.


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  • Matt W1MST, Managing Editor