Random Wire Aerial Info

I use a random wire a fair amount now with the ft817 and HFpacker amp.  Why?  simply put the random wire only requires one high point when putting up, the feed point is down at the ground and the LDG Z100 Pro with a 4:1 Balun or 1:1 Balun gives me all bands.

On our next outing, (which has been a long time, especially since we stopped in Cairns and then relocated to Brisbane) is to Fraser Island on 23 of July for a week.  I will be beaconing on HF APRS Mobile as Vk4KWI-15 and you can look me up on http://aprs.fi.  In the now much smaller 4WD I have installed a TS480SAT coupled to either a diamond mono bander for 20m, 30m or a Maldol HMC6-s.  As we travel generally the 20m and 30m aerials are installed and I switch between them using the TS480SAT's internal switch.

As for the random wire, I figure more wire in the air is better at camp and I get a choice of radios, so the hard decision is sit in the car or sit at the campfire.  Anyway here is the random wire info I use as copied from the writers web site and reproduced here.

"Random" Length -
Wire Antennas
WØIPL

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Many people use what is referred to as a "random length" wire antenna for HF, quite effectively. The problem occurs when the wire ends up being a half wave multiple on one of the bands you would like to operate on. Odd number quarter wave lengths work very nicely. Even number quarter wave lengths (half wave multiple) do not.
With eight bands to contend with, how do you find a good "random length"? Well, what I did was to make a table of lengths that you should not use and then extrapolated out from there. Guess what? No longer random, is it?
Look at the table and you can easily see why a true random length will work beautifully on one band and not worth beans on another.
The formula that I used was 300/Freq[Mhz] = 1 wave length in meteres (spelled with the European trailing e to minimize confusion with meter - a measurement device, i.e. Ohm meter, etc.). Divide that in half to get 1/2 wave length. Thus 150/F[Mhz]. Take that number, multiply by 39.3701 to get inches in a metere, then divide by 12 to get feet. I used 39.37/12 = 3.2808 rounded to 3.28 to convert from meteres to feet.
Final formula is (150/F[Mhz]) * 3.28 = 1/2 wave length in feet. Then multiply by 1, 2, 3, etc. until you exceed my self imposed limit of 125 feet (maximum you can fit on most city lots). Lengths shown are rounded to the nearest one tenth of a foot.

"Center" of band

Frequencies (in Mhz) used for the calculations were: 28.6, 24.93, 21.225, 18.11, 14.175, 10.125, 7.150 and 3.928. Yes, I understand that it has its focus on 75M phone and ignores 80M CW, but it also exceeds 125 feet for 75M phone.

#1/2W	10	12	15	17	20	30	40	75
1	17.2	19.7	23.2	27.2	34.7	48.6	68.8	125.3
2	34.4	39.4	46.3	54.3	69.4	97.2
3	51.6	59.2	69.5	81.5	104.1
4	68.8	78.9	92.7	108.7
5	86.0	98.7	115.9
6	103.2	118.4
7	120.4

Most easily used lengths are: 63', 74', 89' and 111.5'. OR, not very random if you want all band coverage (center of band).

"Full" band

Frequencies (in Mhz) used for the calculations were: 28.0-29.7, 24.89-24.99, 21.0-21.45, 18.068-18.168, 14-14.35 10.1-10.15, 7-7.3 and 3.928.

#1/2W	10	12	15	17	20	30	40	75
1	16.6-17.6	19.7-19.8	22.9-23.4	27.0-27.2	34.3-35.1	48.5-48.7	67.4-70.3	125.3
2	33.1-35.1	39.4-39.5	45.8-46.8	54.2-54.5	68.6-70.3	96.9-97.4
3	49.7-52.7	59.0-59.3	68.8-70.3	81.2-81.7	102.8-105.4
4	66.3-70.3	78.7-79.0	91.7-93.7	108.3-108.9
5	82.8-87.8	98.4-98.8	114.7-117.1
6	99.4-105.4	118.1-118.6
7	115.9-123

Most easily used lengths are: 63', 74' and 111.5'. 89' is omitted because it would be within about one foot in length of two bands on either side of it.
If you want to cover all of every band with minimum loading problems (that does not imply it will be perfect - only that it should load) 74' is your winner.
Department of redundancy department - Not very random to be able to load all bands.
W0IPL

More about Topaz

Where does the time go, so much for my getting to part two about topaz.  It's now even getting to be long enough that I've nearly forgotten where I was up too.  Back into the study and another subject down, that's five papers this year to date and all with good marks.  Makes for being a bit boring in the blog front, thankfully we were able to get some time and escape the city ahnd head out west.

Well who cares where I was at?  Well not me, unless I've bored you with repeating myself.  So to carry on.

What got us into chasing topaz or even fossicking?  I guess the tour was enough to want to try a little more, but the real deal maker was meeting Lesley and Graham.  They were camped just up the hill from us and were planning to be out on the gem fields most days for the next month.  On our second day (I've lost track now and never made notes) I was wandering past their site on the way to the facilities, I stopped for a chat and invited Julie and myself along to fossick with them the next day.

Having only walked around on the gem field at Obrien's Creek I had no real idea where and what to do.  we found out one of the challenges this year is the late wet, meaning wet ground and the difficulty this causes for sieving and finding the gems.  Not to mention the weight the water adds to a bucket of gravel.  On our first day they took us out to a creek bed (now dry), with a shallow layer of gravel (about 30cm/ 1 foot) over granite bedrock.  After some practice in dowsing the creek bed and learning to spot stones in the seive Julie and I managed to find a few topaz pieces.  That was between being regailed with tales of the gem fields and other stories by Graham, tea breaks and lunch breaks.  Graham and Lesley must have had a good day too, they asked us to join them the next day.

Next day was another spot on the gem field, near some equipment Graham had left out a few days earlier in a hole they were working on.  Out came the dowsing rods and Lesley found a spot for her and Graham to work on.  We got the rods for a go and selected a spot to work on also.  This was one day that we found nothing but granite.  Even Lesley was still dowsing topaz in our spot, but it was in the bed rock somewhere and not to be had.  We selected another spot to work on but the day was getting on, we moved a lot of topsoil and and gravel spilt from an old hole by someone else.  No topaz for us, but Graham and Lesley had a great little run, and at the end of the day had found a number of very nice pieces.

We may not have found anything on our third day, but Julie and I were hooked.  On our way home we picked up a mid sized gem pick at Mt Surprise Gems.  Once home I started the process of trying to finding sieves so we could fossick on our own without spending a fortune.  Over the next two weeks I burned the ether looking on the web for second hand equipment then anywhere that sold them new.  At one point I began to think I'd have a better chance at finding hens teeth.  Eventually I found a set of 13" diammeter sieves including shipping for less than I could get anywhere in Queensland.  Better still the set of two sieves, were with mesh sizes appropriate for Topaz, Agate, Garnet, Saphires, Quartz and Zircon.  Why those, well they are all the gem fields that will be close to Brisbane and the sieves are the right mesh sizes and diammeter for the washing process in Zircon, Garnet and Saphire.  The largeest mesh size is also a good for dry sieving for Topaz, Quartz and Agate.

So we are now armed with sieves and a gem pick, already have the spade, we just need the chance to get back out into the gem fields.

Outback again with the radio gear

Can you believe it? It's now nine months since Julie and I unpacked the caravan and took our apartment in Cairns.  Time does fly especially when you take radical changes in life and go back to school again.

After being in the apartment for that long and hanging out to get of the city, even if Cairns is small it is well past time for a trip.  With a long weekend and a couple of Julie's rostered-days-off to use, we packed up and headed south west then west.  Back towards our old stomping grounds near Undara.  However the purpose of the trip this time is to get out to Obrien's Creek Gem Field, possibly scratch around for some Topaz, definitely be out in the sun and heat and definitely do some Ham radio.

The road trip was great, faster and in fact far better than expected, gone or going is the last of the strip seal (2 lane gravel road with single lane of seal in a strip down the centre).  Sealed two lane highway the whole way except for the last bit of road works and a two kilometer piece between Ravenshoe (Ravens-Hoe) and Atherton.  Arriving at Mt Surprise, diet went out the window and I enjoyed three quarters of a devonshire tea, Julie succumbed to temptation and had the other quarter.  Then we also loosened the purse strings of the student budget a fraction and booked a Topaz Fossicking tour with Pete and Pam of Mt Surprise Gems (That gets a blog on it's own in a bit).

Fossicking was booked for Saturday, giving us the afternoon and Friday to get into the swing of enjoying Savannah Country with it's day time heat, cool nights and away from it all.  Being out early we beat the crowds and got the pick of sites by the creek.  Plenty of room for the long wire aerial and plenty of room for us.  Later only spoilt by the townies that set up camp on top of us on Saturday.

That long wire was used on Thursday night to join the Hervey Bay Net on 3615 KHz.  It was so good to catch up with the gang in Hervey Bay, again it has been at least 9 months since I could join this group.  Good signals over a path of around 1500 km (roughly I must work out the straight line distance some time), and other than a couple in the group struggling with their local noise floor I was heard by all.  Gosh I love QRP NVIS on 80m in the evening, it just about never fails.  Friday night the nets just did not happen for me, most were further away in physical distance and 5 Watts was just not enough for good participation by me, reasonable signals though.  Next trip the HFPacker Amp will be repaired and helping out.

The long weekend crowds arrived on Saturday.  Lots of families and kids running around all over the place.  That meant pulling up the radials to save lots of tripping incidents and no radio activity until Monday.  However to make up for it we had a great fossicking tour and learnt what to look for and do when chasingr Topaz.  Added to that we came home with a few pieces too.  That afternoon we chatted to a couple that are regulars out in the gem field and talked our way into joining them over the next couple of days.  Now that was probably a greater, though different experience to the tour.  Nothing like spending plenty of time with a couple of people who know what they are doing and find gems.  We came away from that experience with the fossicking bug, new friendships and a few more Topaz pieces.  Overall for three days of digging, Julie and I came up with six pieces and while they are not the best a couple will look rather pretty when cut to accentuate their faults.

We elected to stay Monday after I had a run in with drinking some bore water.  Piece and quite again as the world packed up and went back home to Cairns or wherever else they came from.  The radials were spread back out again in the afternoon and I had two fantastic QRP contacts on 20m.  One with VK3VBC mobile in Geelong (near Melbourne) and the other with VK3WHO home station South of Melbourne.  Then conditions dropped out, but I did enjoy the long QSO's with these two.  Had a go with 40m but was lost amongst bigger stations calling in from the USA, good signals with 5/7 and 5/8 common.  Even the mobiles were 5/2 and 5/3 but, my 5 watts was not quite enough.  Later on I joined the Mackay net on 3597 KHz and had solid signals into that.  Early Tuesday morning (well we had been getting up early every day to fossick) I was up and decided if I could join in a net with old friends in ZL.  Well I could hear them, however I suspect my inverted L facing west and not east really knocked the signal, they were there and I listened but with signals in my noise floor (which was non existent being this remote) and not even registering on the s-metre no chance of being heard even though I called a few times.  Still nice to hear the team ZL2CVA, ZL1ACM and ZL1RD.

With great reluctance and now feeling better we headed home.  Via Mt Surprise Gems and lunch, plus a purchase towards our fossicking gear.  Our first gem pick, now to build or acquire the sieves, shaker stand and bucket. Leaving Mt Surprise, our thoughts turned to how soon we could come back again to this magic part of the world.

Study Meanderings

I'm getting close to the end of my first four papers. What an effort, correspondence study is tough enough part time and I have struggled at times with focus doing correspondence full time.

My first assignment was great to get done and even better when the mark came back. 100% in my chemistry essay, wahoo! Now keeping that up in more opinion rather than fact based essays will be tougher, but it sure was a great boost to keeping on with correspondence study.

Julie and I have also decided to go down to Brisbane later in the year and attend classes. Oh, by the way Julie is going back to school too. Now we are both into major career changes. So at this stage the intention is to be in Brisbane for the start of Summer School with the Australian Institute of Applied Sciences.

Ham radio took a dive, even after playing with APRS for a while. Though I can say I run a tracker in the car every time I pop out. Sadly even the 2m radio does not get turned on while at home that often, especially when writing assignments. I also successfully established, palm trees are not suitable for long term HF antenna supports, because the fronds come down relatively frequently along with the aerial.

I am not going to chase a mast yet. However the president of the body corporate is supportive (that was a big surprise) and may even help by providing something for a mast. So you never know I might get on HF here when I need some time out.

Looking forward Julie and I are going to get away to the west in June so I will definitely get in a spot of portable operation. On the 3 to 4 week road trip south I will also be getting in some portable operating too. However, updates will happen as we get closer to the time.

Watching the weather

The first Cyclone to affect us is on the way, maybe it will get here in the day Sunday, maybe Sunday night, either way the rain has arrived off the front edge.


Threat Map showing warning and watch regions and likely path.

Satelite image of the Cyclone as it approaches us.

IDQP0005
Australian Government Bureau of Meteorology
Queensland
Tropical Cyclone Warning Centre

Media: The Standard Emergency Warning Signal should NOT be used with this
warning.

TOP PRIORITY
TROPICAL CYCLONE ADVICE NUMBER 5
Issued by the Bureau of Meteorology, Brisbane
Issued at 10:59pm EST on Saturday the 23rd of January 2010

A Cyclone WARNING is now current for coastal and island areas from Cape Melville
to Cardwell.

The Cyclone WATCH from Coen to Cape Melville and Cardwell to Lucinda has been
CANCELLED.

At 10:00 pm EST Tropical Cyclone Olga, Category 2 was estimated to be
250 kilometres east northeast of Cairns and 365 kilometres north northeast of
Townsville, and was moving west at 21 kilometres per hour.

GALES are expected to develop about the coast between Cape Melville and Cardwell
on Sunday.

DESTRUCTIVE WINDS are likely to develop about the coast between Cape Tribulation
and Innisfail on Sunday afternoon as the cyclone centre approaches.

Very heavy rainfall with localised flooding is expected to develop about the
North Tropical Coast during Sunday.

As the cyclone crosses the coast, abnormally high tides are expected between
Cape Tribulation and Innisfail, but the sea level should not exceed the highest
tide of the year. Large waves are likely along the beachfront.

People between Cape Melville and Cardwell should immediately commence or
continue preparations, especially securing boats and property.

Details of Tropical Cyclone Olga at 10:00 pm EST:
.Centre located near...... 16.2 degrees South 148.0 degrees East
.Location accuracy........ within 35 kilometres
.Recent movement.......... towards the west at 21 kilometres per hour
.Wind gusts near centre... 140 kilometres per hour
.Severity category........ 2
.Central pressure......... 983 hectoPascals

The next advice will be issued by 2:00 am EST Sunday 24 January.


This warning is also available through TV and Radio Broadcasts; the Bureau's
website at www.bom.gov.au or call 1300 659 212.  The Bureau and the State
Emergency Service would appreciate this warning being broadcast regularly.

Being stealthy at Yorkeys

Wanting to get better VHF coverage I tried to be really clever idea with a slim jim to get it way up in the air above roof line three floors up and operate an APRS Digi at my place. I can hide the aerial from obvious view but getting coax there well that's another story and one that will not go down with the body corporate and possibly the neighbours. So back to one hidden in the court yard that gets me onto local repeaters, until I come up with a cunning plan or something a little left field for a solution to get better coverage for APRS.

I tried using the FT8900 in the Landcruiser today in cross band repeater mode but noticed the tail in the cross band coupled with the relay delay in the audio interface inside really did not work for digipeating, still I was decoding data from VK4GO's digipeater. Then UIview started acting like it was deaf or was it the lap top but still had Audio coming in. Hmmmmm looks like I will discount using that interface with digipeating and the cross band, still I am all set up for digital modes. Turned the digi off in UIview and still no decoding on receive.....look into that tomorrow....or maybe the path went bad in the middle of the day. Lets look at the cross band again tomorrow and see what happens. The other hassle with this solution is I thought of using the solar panels to keep the car auxillary battery topped up but they will be in shadow. There is power right beside the car, maybe I can do something there to float the auxillary battery.

Taking the cross band out of the loop and not relying on my audio interface to digipeat is probably a good idea. I recently sold the magnetic loop I brought over with me and bought a digipeater by Fox Delta, now if I put that in the car when I am parked up at home could solve the problem, which is what side of the building the aerial is on. Well part of it at least and I can work on a power supply or charging solution for the car and a good place to park the car for receiving VK4GO's digipeater and my beacon. Power out put from the FT8900 would also be useful too for transmitting.

A few days after typing this I was listening to the APRS signals from VK4GO and thought I should be able to decode those. It was an S2 signal but nice and clean, but the PC just acted like it was deaf. I had been loaned a APRS Foxview by VK4GO, a nice device that decodes UI Packets and displays them on a LCD screen. Plug the audio in apply power and hey presto packets decoding in front of my eyes. Well, well, there must be an issue with my sound card and software sensitivity with regards to signal to noise because it want at least S5 to start decoding and very little noise.

Hmmmm, time to get the Foxdigi going inside without using the car in the middle. Just the incentive I needed to hook up a tracker with GPS and get the Digipeater going as well.

12V ponderings

I've ended up with what I considered relatively slick portable operation for travelling. Easy to put up aerial...it's a long wire over trees. And there have been plenty of trees around. Good radio and Amp combo with the FT-817 and HFPack Amp and of course the LDGZL11Pro with 4:1 Balun to make tuning a breeze. Massive (120W) solar panel to recharge the car battery or the caravan battery so always had plenty of power and been to places with plenty of tall trees.

Now I live in an apartment, ground floor level, plenty of 240v, but car and caravan prohibitively far away. Oooops I never planned even in my wildest dreams to be in an apartment. So much for planning for all possibilities, then again Julie and I both thought we were going to be in the caravan for the whole time.

Now what to do for 12v DC power...with the ft-817 and HFPack amp all I need is 11.5 to 12V. I'm back to school soon, so for now out the window goes the idea of buy a lovely new power supply even a cheap one. What ever I doo need to fit a budget of arouns $20, so time to put on the thinking cap and get outside the square.

Only needing 15 amps maximum the supply requiremnt is not huge. I started looking at converting ATX12V or the ATX12V2 supplies...good possibilities. Now to find an old PC to pull apart and a few bits and I'm away. Or look around for a retired but not dead battery and hook the solar panel onto it full time. Options, options, time to see what I can find out there.

Anybody out there around Cairns with an old PC power supply to give away and/or a useable battery I'm interested.