Counting - Radio #2 - Yaesu FT-817ND - 20m Delta Loop - Cheap, Lightweight, Portable and with Gain

I have been asked before if I had to take the minimum amount of radio equipment to a remote location what would I choose.

Chatting about this with other radio amateurs one can easily conclude that there aren't identical answers. Everyone has it's own preference, so what I am about to write is my *own* preference.

Here is goes:

• The Yaesu FT-817ND. Very nice little radio. All bands, all modes, in a very tiny and competent package.

• For working several bands you cannot go wrong with the LDG Z-817 tuner. It's a nice match with the FT-817 and with the interface cable it all comes together extremely well (in a all automatic fashion).

• If you hate automatic tuners and you want a cheap but efficient option, then my choice goes to the beautiful QRP Projects ZM-4.

• For the power source, I usually go with a 12V/7Ah SLA battery, although on a really remote location I would also take the PowerFilm F15-600 10w Folding Solar Panel Charger, good for 10 watts of power, at 600mA.

Now, it's when it comes to the antenna that we all make different choices.

I have spent many hours looking for a cheap, easy to build, easy to carry, easy to erect, with gain antenna to conclude that the best compromise possible is the 20m Delta Loop. This antenna, when properly built, will present itself as a 50 ohm load at the resonant frequency and it will offer you 2.78 dBi gain, which is 0.65 dBd gain, in freespace. It will also work (with a tuner) on 40, 15 and 10m.

Here's how my loop is setup and what what you will need to build one yourself.

Resonant loop antennas have a feedpoint impedance of about 100 ohm. There are many ways to feed a loop antenna. For me, the most practical way, is to use a 4:1 current balun. On my loop I am using a commercial balun, a 4:1 Guanella current rated at 150 watts pep, 50 -200 ohms. The one I am using is from G-Whip Antenna products and at about 25£ it will not break the bank. It's also a quality product with stainless steel hardware, designed to last on permanent installations.

Now, for feeding the delta loop antenna you have several choices:

I went for option D, Apex Up, Corner Fed. This setup allows Vertical Polarization. This will give you a low radiation angle, which is the best choice for DX. It also has the advantage of requiring only one central support as I will illustrate latter in this post.

Calculating the loop total size is actually quite easy. To make things even easier you can use this online loop calculator that will do all the math for you.

For 20m here's what I got:

To be more precise, for 20m, mid band (14.175MHz):

Total Wire Length: 21.61m
Delta Loop, one Side: 7.203m
Height (Base to Apex): 6.238m

Although it's true that feeding the loop at the bottom corner will give you predominantly vertical polarization, feeding it a quarter wave down from the top middle is theoretically better.

Since each size is 1/3 of the total length, finding the correct feeding spot is quite easy. Just divide the full length by 4 to get the necessary 1/4 measure:

1/4 of the total length is 21.61m / 4 = 5,403m

So, your feed point location would be 5,403m measured from the apex, or, if you prefer:

7.203m - 5,403m = 1,80m

That would be 1,80m from the base (corner point) to the feed point.

Finally you need a practical way to set the loop up. A cheap fiberglass pole is the right way to go. My choice is the Essential Pole 700 from Caperlan. It's 7m when extended although the last 1m section may be a bit to fragile for antenna usage,

And here's how it all goes together (10 minutes is about the time one takes to erect this antenna).
The complete antenna:

The 4:1 balun:

The mast, when extended:

And, of course, when properly packed this is an antenna that fits nicely into a small plastic bag.

So, there you have it. Cheap, small, lightweight, easy to carry and with some gain. My favorite simple antenna for portable operation. What's yours?

PS: For some QRP Delta Loop action make sure you watch Peter, VK3YE video on YouTube.

Counting - Radio #2 - Yaesu FT-817ND - Operating QRP Portable

It's now almost mid April 2014 and finally the time has come to take a break from work.

I headed for bluer skies and landed a spot in the south coast of Portugal with enough free space for playing around with some antennas.

To be honest I have/had very little prior experience while operating QRP portable. I did one SOTA activity with my good friend Pedro and while he scored quite a few CW contacts I came out empty handed on SSB. So I knew it was difficult. I just did not know how difficult it would be.

So, here's what I had available for my portable station:

• Yaesu FT-817ND
• LDG Z-817 antenna tuner
• 12V/7Ah SLA battery
• G Whip Widebander Antenna
• Spiderbeam HD 12m fiberglass pole
• M0PLK Multiband Delta Loop Antenna (available at location)
• A 6m aluminum mast (available at location)
• A 2m TV arerial mast.
• Several bits and pieces, like coax cables, connectors and  mixed tools.

So, on my first day, the 13th of April, I started out with the 12m fiberglass pole and the Widebander Antenna. Here's a shot of the 12m pole installed and ready to be pushed up:

As I was setting the Widebander I noticed, again, the great quality of the 12m Spiderbeam pole. It's quite heavy and probably not suited for the SOTA operator, but still, for a place-it-the-car-trunk mast, you probably cannot beat it for it's quality and price.

As I raised the widebander it became clear that even a 12m mast is not enough to extend all the wire in the antenna. Perhaps I should have read the antenna description:

"The G Whip wideband antenna comprises of a super efficient 9/1 un/un and 2 lengths of kevlar wire, the 22 mtr radiator and a 20 mtr counterpoise are supplied. Resonance/matching is achieved with a good trans-match from 3.6MHz to 50MHz with a maximum VSWR of under 2 to 1. (not tuned as you cannot tune an antenna with an ATU, you can only match it!). Sloping radiator length is approx 22 mtrs which can be dog legged."

So, while it's a great idea, this antenna requires a lot of space. And I just did not had that space available at the time.

I ended up by not extending all the antenna, and I am sure that affected it's performance. Nevertheless the antenna tuner was able to match the antenna from 10m to 20m with no problems whatsoever.

At the end of the first day I was quite happy as I had managed a good 20m QSO with the island of Tenerife, with EA8/I0SNY. This accounted for a distance of 1286,24 Km wich at the time sounded very good for 5 watt only.

As day one came to an end, I started thinking if the distance I had managed could be further extended. So, even before sunset I started preparing for day two, where I would be changing the widebander for a multiband delta loop. I was hoping the delta loop could give me better results. And, as it turned out, I was not mistaken.

As day two started I was able to get the delta loop up and running.
Here are some photos of the day two setup. First the QRP station:

And the *star* of the day, the multiband delta loop antenna:

As the day progressed I had no doubts that this is a superb antenna. It's actually so good that I am considering having one permanently setup at my QTH to use as a second antenna.

Propagation was not brilliant on these days but I could easly listen to DX stations on North America, South America, Australia and New Zealand. This is how good this antenna is.

Of course, when you are working with 5 watts only it's not likely that you will break pileups. Actually, you will be lucky if a DX station picks up your signal, Well, I was lucky enough: I managed a contact with PY3MN, located on the south part of Brazil, very close to Argentina, for a total distance of 8873,49 Km. I was very happy with this contact as it stands as my best effort with 5 watts only.

I have written Ben, PY3MN to thank him for the contact. In fact, if it wasn't for propagation and his mighty antennas (Hygain TH6DXX 10-15-20 “6” element triband yagi and Moonraker AV140 4 element 10m monoband) this contact would not have been possible.

Just so you can have an idea, here's what a Moonraker AV140 looks like (no, it's not a 4 element cubical quad!).

Anyway, what a great day. These are the days that for us, ham radio operators, stay in our memory for years to come.
Until other blog post, I will leave you with the sunset for that particular day.
73 and see you on the bands.

M0PLK Multiband Delta Loop Antenna

Those of us that are into ham radio know that one of the most important parts of a radio station, if not the most import part, is the antenna.
Most of the hams I know have spent, or a willing to spend, hundreds of dollars in transceivers. When it comes to the antenna system, well... it's a different story!
Today I will write about a commercial antenna design that I find interesting enough to write about. It's the Multiband M0PLK Delta antenna
Here's why I find it interesting.

1. It's a muliband antenna. Performs well on 20-17-15-12-10m.
2. It can be used on the lower and higher bands (with reduced performance).
3. It's a loop, so it has a low angle of radiation. This favors DX contacts.
4. Since it's a single loop, it's bi-directional.
5. On a permanent installation it only requires a light duty rotor (a TV antenna rotor) to rotate the antenna.
6. It can be turned by hand, with minor effort, in a portable operation.

It can be home-built in a light-weight format, turning this antenna into a very interesting option for those of us who do SOTA or operate portable.
So, what does this antenna look like? Here it is:

The loop is formed my two aluminum "arms". On top of each arm, wire is used until the feed point. Here's a pictures showing this particular connection:

The feed point is then fed with ladder line that comes down into a balun. After the balun the usual 50 ohm coax is used.
Here are some pictures of the base of the antenna, including the balun:

This antenna is, at this time, commercialized at about 225€, that is about 300USD. Here are a couple of places where you can buy it:

• VPA Systems
• UrBasket.eu 
• UrBastket ebay shop (here you van actually make an offer for the antenna).

If you curious about the antenna designer you can find him at QRZ,com.
And of course, you can read this antenna reviews on eham where it currently rates exceptionally well.

As I own two of these antennas my experience dealing with Artur (M0PLK) was the best. Just to show how good the support is I will share a quick story: when I bought the antennas I had plans to use them right away. Unfortunately when the antennas arrived my job position had changed and I was loaded with work. I had no choice other to check what had arrived and store the antennas, waiting for a better day to use them. Time went by and one year (yes, you read well, one year) latter I found the time to assemble the antennas only to find out that there were a couple of parts missing (some clamps; simple parts really, I should have checked). I e-mailed Artur anticipating that we would ask me why so much time after buying I was asking for missing parts. I never received such a question. Instead, at his suggestion, Artur sent me the missing clamps for the antennas. No questions asked. How's this for support?
So, whatever you do, buy or build your own multiband delta loop, have fun and happy DXing.

 Here are the dimensions of this antenna:

Mini-Whip active antenna 10kHz to 30MHz

So, what's the story with the active antenna?
A few years ago I assembled a PM-SRD software defined radio. I needed a small and low profile antenna for the SDR. After some googling I ended up selecting the Mini-Whip active Antenna.
The Mini Whip ative antenna was invented by Roelof Bakker, PA0RDT.
For a detailed explanation on how this antenna works, try here and here.
For now, I need to sort out the missing stuff for ths project. Here's the list:

1. I need a 12-15V small power supply, capable of delivering 50mA.
2. I need 3 x SO239 (or BNC?) Chassis Mounting Female Sockets.
3. I need some small 50 ohm coax (RG-316 or RG-188).
4. I need to come up with some sort of PVC housing for the antenna.
5. Also, I need some housing for the antenna supply module.
6. Finally, after all is done I need to sort out some kind of a plastic mast to raise the antenna.

So, tomorrow I'll get this list on the way.
Hopefully, in the end, I'll get something like this: