Wire Length For End Fed Random Wire

I thought I had written about this once before but I looked into my archives and found nothing.  I did do tests previously on 44 feet of wire for my EARCHI Matchbox and I thought I would revisit what the optimum length is for a random wire.

The random wire antenna is probably one of the least expensive, easiest and cheapest HF antennas to use if you have a tuner and you want to get the "most" out of a length of "random" wire without having to pull out that calculator, doing the math, getting the center insulator built or bought, running the feed-line, and all the rest that goes with putting up a more elaborate antenna.

However, there are lengths to avoid because if you pick that wrong  length, the tuner may not work in one or more bands

Jack, VE3EED, solved the major headache of doing all the math of figuring out what the multiple of half wavelengths of the ham bands are.  These are the lengths to avoid.

So in a nutshell - Here are the lengths to use which form a sweet spot for tuning all the ham bands.  All the numbers are in feet.  Make a note of it.

29  35.5  41  58  71  84  107  119

Well does it work?  Before I settled on 41 ft, I used 50 feet which is also OK but I found that with 50 feet 80m is difficult to tune.  41 feet is much better.  I did give up the tunability of 30m but the tuner in the KXPA100 does not have a problem.  All the other bands are a cinch and 12m is almost resonant.  All the SWR figures will change with length of feedline so don't worry about it and let the tuner do the work.

VE3EED is now SK but the internet article can be found here

http://www.hamuniverse.com/randomwireantennalengths.html

The visual solution to the coding that was done Jack is here

http://udel.edu/~mm/ham/randomWire/

Contacts made with the end fed random wire using the EARCHI matchbox  are all with 50 watts and the KX3/KXPA100 are G0ORH, KR5N, MI0AHH, EA6NB, EA8/DL2DXA  CO8LY on the WARC bands during the tests I conducted today.  This will serve as my backup antenna for the DXpedition to Saint Pierre.  It can be deployed as a dipole or an inverted L vertical.

DXpedition Planning - Lessons Learned

(1) Never assume that anything is admissible to the airline as far as checked baggage goes

• Case in point – I assumed that my tiny 450 watt generator when inside my checked luggage is OK with the airlines.  Once inspected and if there is any smell of gasoline – the generator will be confiscated.  Research this ahead of time.   I re-thought my power source and settled with LiPo batteries when operating away from commercial mains
• Make sure the size of any tripod is under the limit that will otherwise classify it as oversize baggage.  This can be quite expensive $175 one way.  Stay under the 62 inch limit L+H+W <62 inches.  For my tripod, I had to fabricate a box that was 46 inches high and 5 inches wide and 4 inches deep which is about 54 total inches – which is inside the parameters set forth by the airlines
• Make sure your rig fits in a Pelican Case sized for carry on size limits – the Pelican 1520 is the largest case that fits these parameters.

(2) Make sure you research the QRN and man-made noise sources are minimal in the places you need to operate from.

• I learned from previous DXpeditioners that areas close to the city center in Saint Pierre tend to have a lot of noise and so I sought out a place that was on the outskirts of town
• In addition I gave myself the ability to relocate using batteries as a power source

(3) Take advantage of verticals near the ocean

• I did a lot of research on the advantage verticals have over yagis for DX when operating close the ocean, and there are several for a solo DXpeditioner, weight, gain, omnidirectionality all contribute to the vertical being the solid choice and performer
• b. A single elevated radial is all that is needed because the ground plane conductivity and reflective properties overwhelm the directivity.

(4) Don’t take on the role of a solo DXpeditioner unless you have several field day and extensive contesting experience, operating split, and operating long hours in the saddle.

• Nothing prepares you for the rigors of a DXpedition than contesting – that is making QSO’s for hours on end.
• You will be more successful if you are an experienced contester because you can maintain high QSO rates.  You don’t want to kill yourself but an operator who is comfortable running 150-200 Q’s per hour with a DX exchange is going to be less “under the gun” than an operator who can only operate at 50 Q’s per hour.  The 50 Q/hr operator will feel guilty about not making enough QSO’s and not take breaks – end result – burnout and a not so pleasant DXpedition experience.  Remember, you will be all alone and need to pace yourself.  
• Field Day experience allows for less stress in set-up and break down because you know the routine, you know just how much or how little to bring, and is comfortable with having to lug equipment.
• Operate as many Field Days as possible ahead of a planned DXpedition.  In my case I have participated in 4 Field Days prior to taking on the DXpedition mission.  On the last Field Day prior to the DXpedition, I am simulating activating an island and set up on a beach with the same equipment I will take to the DXpedition.  I will be doing this in Hunting Island SC for Field Day 2015 with the call sign K4J and with WM4AA.
• Operate as many contests as possible ahead of the DXpedition that your schedule will allow.

(5) Take inventory of everything and prepare backups for any piece of equipment that might be prone to failure

• Extra bolts and nuts, clamps, etc.  Guy ropes and stakes
• Weigh everything and be prepared to pay any extra luggage fees.
• Minimize the weight but maximize redundancy.  These are competing goals – so weigh the risk-reward carefully
• Make a list of everything you bring – and make it some sort of a checklist (so you don’t lose anything as you set up and break down
• Bring an extra headphone, keyer, and make sure you have programmed NIMM to function with the main rig and a back up rig.

(6) Know how to operate your rigs and antennas efficiently

• Again nothing prepares one for this other than contesting, operating split, using morse and voice keyers, contesting software (N1MM, Win-test).  N1MM is my first choice.  N1MM has a DXpedition mode that allow you to log Dupes.
• Know the current draw at the power levels you intend to operate.  If the propagation is good – cut back on power.  You are the DX and you have an 18 dB advantage over the chasers
• If the pileup gets too heavy – turn down the power.  The big boys with big towers and sensitive receivers will still be able to hear you and work you.  When the pileup gets too thin – turn up the power.  This is the tip from Vlad N3CZ who has activated many a DXpedition.
• Know how use your rig as an antenna analyzer as a backup
• Know how to use your antenna analyzer efficiently
• If you have to paper log – make contingency plans that allow you to do this – have a handy UTC time source and an all-weather notebook (just in case your laptop battery craps out).  Make sure you have an extra paddle or two – just in case.

(7) For making audio and video recordings

• Make sure everything in the audio chain works and practice using your sound capture software ahead of time.

Plan B - Power Source for the DXpedition

I have researched the airline regulations concerning small generators in checked luggage.  Generators have never been small enough to be packed into a a piece of luggage.  With the PowerHouse 500 Wi, it is small enough to be packed into a suitcase.  The question is, will it be accepted by the air carriers?  Some carriers will accept it as checked luggage provided it has never been run and never filled with fuel.  Some carriers will not allow it in any condition.  This forced me to rethink my power source for the time I am away from commercial power.

Plan B is to use Lithium Iron Phosphate batteries.  They have 1/5 the weight of the equivalent capacity SLA (sealed lead acid) and have a deeper discharge (80%) before needing a recharge.  The KX3 will stop working long before the battery reaches a deep discharge.  I just need a charger now that will work with 220V and 50 Hz commercial power.  I will also need to sell the generator I acquired.

I found a voltage converter at Batteries and Bulbs which will step the voltage down from 220 to 120V.  I also found a 3.5A charger that will charge a Lithium Iron Phosphate battery in the same store.  I found 35Ah and 24Ah Lithium Iron Phosphate batteries at Amazon for a very reasonable price.

Aerial Tour of Prince Edward Island

Aerial Tour of Prince Edward Island

Bill N4IQ, Bob ND7J,  Phil AC4Q

It would be a good idea for us to take a similar tour and do a video/slideshow documentary operating from various places around the island near the ocean.  We will have a rig and portable antennas to make this possible now.  We can put that into our planning.

My one vote is to visit Avonlea, site of the movie Ann of Green Gables.  This movie was shot entirely in Prince Edward Island.

Anne of Green Gables is a 1985 Canadian television drama film based on the novel of the same name by Canadian author Lucy Maud Montgomery. The film starred Megan Follows and was produced and directed by Kevin Sullivan for the Canadian Broadcasting Corporation. It was released theatrically in Iran, Israel, Europe, and Japan.

The film aired on CBC Television as a two-part miniseries on December 1, 1985. Both parts of the film were among the highest-rated programs of any genre ever to air on a Canadian television network. On February 17, 1986, the film aired on PBS in the United States on the series WonderWorks.

If you ever have the chance, try to watch the movie - a great family movie.

Ariel

Testing Antennas for the DXpedition

Omni-Angle

I put up the 17m OmniAngle to see how it would perform in a real world situation.  Height AGL is about 27 feet.  SWR was 1.2 at 18.069 MHz so tuning was OK.  7QAA was on the air. 7QAA is some 8100 miles in Africa.  I was in the pileup with about 80 watts of power - barefoot on the KXPA100.   7QAA was peaking out at S4 on the PX3 with the Hexbeam pointed 87 degrees.  The omni angle was about 1/2 S unit down on the Hex.   I decided to work 7QAA in the pileup with the Par Omni-Angle at 80 watts.   Well - what do you know, without turning the amp on I was able to work 7QAA.  The Par Omni-Angle was on my deck.

Crank-IR

Wow.  This antenna is super easy to put up and tune.  Got the SWR at 1.2 at first try.  Moved the radiator an inch to tune it down to 1.0.  The radial is super easy to set-up.  I already used my NY4G call.  I used my ex call AJ4YM to see if 7QAA will come back. (Side Note - NY4G is so much easier to key up than AJ4YM) .Two calls at 200 watts and no problem.  Again, the CrankIR was only down 1/2 an S unit on receive.  The CrankIR was half an S unit higher noise floor.

The video below was only a receive comparison

Here are images  of the CrankIR 

St. Pierre and Miquelon DXpedition Update

March 16:  I was able to get more support.  Supporters  now include the following:

Don C Johnson
Matt Collier WM4AA
Tom Rouse N0TR
Dave Watson W4DJW
Scott Zemitis
Matt Holley KU4XO


March 9:   I made a presentation at the Greer Amateur Radio Club and made an appeal for support.  Thanks to Tom Rouse's and Bernice's generosity, I am a little bit closer to my goal.  Dave Anderson was looking to loan me a backup rig.

Anyone wishing to contribute may do so in the following link:

Support and Funding Website

The SteppIR antenna came in via UPS.

I was able to order the pelican case for the main rig.

This coming weekend I will be conducting tests on my equipment especially the 450 watt generator - to make sure it runs.

Informational Presentation at the following link:

For additional Info

Challenge and 30m DXCC Awarded

The long awaited time has arrived.  It seems like a marathon and feeling like I crossed a tape across a finish line.  It really is more of a milestone.  It is ironic and apropos at the same time that I got all three - 5 band DXCC plaque arriving, and Challenge, plus 30m DXCC all on the 5th year anniversary week of my first ever QSOs on HF.

5 Band DXCC Plaque Came In the Mail

This week marks several anniversaries:

My first HF QSO is to maritime mobile station on March 2, 2010.  My second HF QSO and first land based HF station is a lighthouse on Moose Island in Maine AA1KS, the same day.  This week is my 5th year anniversary from my first ever HF contact (almost to the day).  This month is my 5th year after having the General Class upgrade.