Thursday, April 10, 2014

LDG Z100 Plus Autotuner

I've been getting a little tired of manually tuning up the K2 with my Tokyo HC-400L tuner. I know it’s me being lazy and I should know better, but hey when there’s an auto tuner out there that will do the job for you well, what the heck! 

Having my three transceivers connected up at one time means that my set up is a little different. I have three antennas, the cobweb, my 30 meter vertical and my W3DZZ trap for 40 and 80, so I have all three connected up to my Tokyo ATU and then to a homebuilt connector box which switches over to each individual transceiver I want to use. 

When operating with the Yaesu FT1000MP MkV I can bypass through the Tokyo and use the auto ATU from the FT or when using the K2 or OHR100A I can use the manual override and manually adjust the ATU for each radio. Complicated? No once you get used to the idea it works fine! 

The LDG Z100 will be set it up through the K2, so it will be K2/LDG/ with the bypass set on the Tokyo, and then through to the connector box on out to the antenna. To be honest I wasn't sure it would work, but it does and I'm getting out OK. I’ve only tried QRP as I don’t want to tempt fate just yet but the ATU is tuning up nicely against the K2 and so far so good. 

In the UK the LDG Z100 retails for around £140 which is a fair sum, but I've been meaning to purchase one for some time and I thought I’d probably have to go down the 2nd hand route. Luckily I found a site on Ebay, a Greek radio dealer who was selling the ATU for under £120, a fair bit cheaper than the UK, so I bought one. 

It arrived well packaged and only 5 days from ordering, so first impressions on opening the packet are pretty good. Nice clear instructions are provided and it’s dead easy to connect up with the usual TX and RX coax inputs, a ground and a power connection for 7–18 VDC 100ma. I’ve connected power via my PSU for the K2 and it works fine. 

Initial tuning is pretty easy, you have to select the required band, transmit a carrier and hold the tune button whilst the ATU does its business, all very quick and efficient. I've done a couple of QSO's and all is behaving as it should so touch wood I'm very pleased with this little ATU. Now I’m looking forward to having a real play and thankfully no more trying to remember the settings for each band and adjusting the manual controls on the old Tokyo.

Wednesday, April 9, 2014

MFJ 259b Antenna Analyzer - An Update

Going over some previous post I see that a lot of people have read my little summary of the MFJ 259b. This is what I originally said: 

"The MJF 259b has finally arrived, it’s a fiddle though, you would have thought you’d get the power supply with it, but no, that has to be ordered separately, typical! So now I’m busily checking around the local hardware stores for an AC DC adapter with the right connector, it never comes easy does it? 

On surfing the web I came across a UK Amateur dealer who wanted £68 for the MFJ 99x accessory pack which includes the dip meter coil, carrying case and you guessed it the power adapter! Having checked out the web I can get a power adapter for £6.50, makes you wonder doesn’t it? 

The other pain is that I knew it took rechargeable batteries, but I was rather taken back when I realised it needed 10! Removing the front cover to install the batteries requires the removal of 8 screws; you'd think MFJ would have come up with a simpler design? 

However I digress, last night I popped round to my next door neighbour and asked if by any chance he had a 12v power adapter, he did and blow me it fitted! So I was able to do a quick test to make sure all was working as it should, interestingly enough all my antennas were slightly out on the SWR readings, most likely from the recent storms, but over the weekend as a simple experiment I will borrow my Brother in Laws MFJ that I originally used to set them up to see how good the SWR matches are on both units, that could prove very interesting!!" ...........................

I never did complete the last bit until much later, well it turned out that my MFJ wasn't too far off my brother in laws, I must admit I was expecting it to be way out.

Now that I've owned this piece of kit for some time and am a regular user I am probably now able to give a better report. The analyzer is actually a very useful especially if you are in to or going to make any sort of HF VHF antenna system. It's fairly easy to use with simple instructions, but if you get stuck just "google" and there are plenty of users out there who will help you.

However, in my humble my opinion it's not that well made, it's rather tinny, it doesn't feel very solid and to be frank feels rather cheap, but of course we owners know it don't come cheap; £300 plus I believe is the present asking price for a new one, so spare your blushes go 2nd hand if you can, believe me they are fairly easy to fix!

Mine does have some drawbacks, somewhere within the area of the coax connector there is an intermittent short, so whenever I connect up my coax cable to the connector I have to fiddle about to make sure I have a good connection otherwise I get a reading or +25 on the SWR. 

I've tried to find this short but it still is escaping me at the moment and it very annoying. More to the point it’s been there since new which doesn't exactly give me any comfort with MFJ products especially since they all seem very expensive! 

I have extra bits I've made for the analyzer, I'm not going to purchase any bits of kit if a) I can make them and b) they are always far too expensive!

The loop coupler I use for measuring my homebrew traps; It’s dead easy to build and I strongly suggest you build rather than buy otherwise you may find yourself spending a large amount of money for what can be made in a jiffy at very little expense. 

If you have a good soldering gun you just take was some reasonably thick copper wire (about 6” in length) bend in a circle but keep ½” of each end straight. Take a male to male 259 connector and it’s a simple case of soldering one end of the wire to the centre pin and the other to the outside ring. So you finish up with a circle of Copper wire attached to the male to male 259.

The other piece of kit I made was a frequency counter lead out of some coax and with a PL259 connector at one end and the probe on the other. I used this for working out the frequency measurements on my K2, very useful and very cheap!

Overall, an essential piece of kit for the shack, but there are other analyzers out there at a cheaper price that do the exactly the same thing. In other words, "you pays yer money and takes yer choice!...Hope this helps.

Revisiting the 60 Meter Band

Having been somewhat dismayed when I first listened in on 60 meters I thought I’d better give it another go and see if the awful abuse I heard before was just a one off incident. 

So I put the old inverted vee back up and had another listen to see what was about. There were a few amateurs on sideband and some interesting conversations, but quite honestly I am still surprised how quiet the band is, I didn't hear any CW at all. 

For the past week I've listened most mornings, afternoon and evenings but I can probably count the number of amateurs I've heard on one hand. Admittedly the band is used on a secondary basis but it is very quiet. 

Then finally on Monday afternoon whilst sweeping across the band I crossed over 5.325 heard some voices, so I fine-tuned and there they were, back again, swearing and cursing with the most obscene language and believe me I'm no prude! 
I appreciate that not all users of 60m are licensed amateurs and 5.325 is not in one of the UK 60m frequency blocks but listening to that language does put me off. By the sound of their accents they were from the South West, possibly Gloucestershire or Bristolian and they seemed to be talking a lot about fish, so one can only guess these are local fishermen. 

It’s a shame really because 60 meters can be a great band, I remember back during my military days being stationed for a while in Belize and having to set up a radio station to contact our main base which was at Bruggen in Germany. 

I worked with a Royal Signals chap who was very knowledgeable and together we set up a nice little radio station by the main runway of Belize airport with a massive dipole system and over a period of weeks we had some great contacts with other military establishments all over the States. 

We actually had some success with Europe contacting the base at Bruggen on a number of occasions and I specifically remember using 5 MHz for a few attempts and managing some reasonable contacts!

Tuesday, April 8, 2014

Playing with a HyGain 18-VS

The other month we had our local radio club junk sale, everyone brings in something to sell and we have a good natter and lots of items get exchanged. It’s normally a very good event and gives all the members a chance to catch up and see what we are all up to. 

I brought in a tired looking 2m collinear and my home brew 2m yagi to be redistributed, both items had been sitting in the shack doing nothing and I needed the room for other projects plus they could be put to good use by another amateur instead of sitting there doing nothing. 

Whilst rummaging around looking at what other people had brought in to sell I noticed a chap with an old Hy Gain 18-VS vertical multi-band antenna. I vaguely remember my brother-in- law having one but always being a little frustrated because on each band change you had to go out to the antenna and manually alter the connection to the coil. To add to his frustration he always forgot the exact position he should set the connection and always ended up digging out the antenna analyser and resetting the SWR! 

This particular antenna in the sale looked like it was all there, but it certainly needed a good clean, the owner only wanted £10 and considering that a new one was over a £100 I thought I’d buy it and have a play to see if I could do something with it. 

After giving it a good clean and checking the manual I immediately realised that the antenna had been altered. Instead of the usual tatty coax connection above the coil, a previous owner had put in an SO 239 socket at the bottom of the antenna to make things a bit tidier, however, with that connection in place the coil was being bypassed therefore was useless. 

Investigating further I realised that the antenna had been set up as purely a mono bander, the previous owner had obviously given up on the state of the coil and from notes in the manual they mentioned about removing 12” of tubing, or he must have been like my bother-in-law and got fed up with changing the coil every time he wanted to alter bands! 

The two coils after a quick clean up, no doubt in the future I will put them to use.

With the antenna originally at 18ft in length I rightly guessed it had been reset as a mono for 20 meters but in its present state it wasn't going to transmit or receive anything. So I took it all to bits, and started from scratch, the coil looked in a sorry state, it had been glued together at some stage and so I removed it altogether since in its present condition it was certainly not going to work. 

After a good clean and checking the rest of the connections I reset the antenna length to roughly 16½ ft and connected it up to my analyser, all now seemed much better with an SWR of 1:1. 

So then I planted the refurnished antenna next to my 30 meter vertical via an old piece of scaffold pole hammered in to the ground. Using the 30 meter ground wires I attached some thick copper wire to the ground plate and I was now all ready to connect to the radio and have a listen on 20 meters. 

You wouldn't believe there are 30 odd ground wire connected to that plate!

Sure enough signals were coming in and after double checking everything was correctly connected I did a quick transmit through the dummy load, everything worked perfectly. Calling CQ I immediately got a reply with a signal report 599 from another QRP station in Italy. 

The HyGain planted next to my 30 meter vertical

Very pleased with the outcome I did some further testing against the 20 meter portion of the cobweb; however the cobweb was definitely stronger no doubt because its thirty odd feet up in the air and clear of all surrounding objects. But never the less it was great to get hold of an old Hy-Gain and bring it back to life!

Sunday, March 30, 2014

Swapping Over the Cobwebs

Last Friday evening in a bit of madness during a bout of boredom, I decided to dig out the dismantled G3TXQ cobweb from the attic and set it up outside in the garden. I’d wanted to re test it against the present G3TPW cobweb I'm using, just to go over the pros and cons and possibly replace the G3TPW. 

With the G3TXQ quickly set up on a piece of 6ft scaffold pole and after doing an approximate tune I couldn't believe my luck when wondering over the 21Mhz band that I managed to have a qso with a Russian station who gave me a 599 which made me think maybe it was time to swap the cobwebs over. 

Saturday morning I set to work and I did the full tuning with the MFJ 259 which took an age as the G3TXQ definitely has much finer tuning points, it dips very quickly and the freq range is literally a few hundred kilohertz, a noticeable difference to the much wider freq of the G3TPW. 

Because I was tuning/trimming the antenna with the MFJ 259 at only 6ft above the ground I had to take the risk of setting each of the elements to tune a little lower than the freq I wanted to operate on, the theory being that once raised the SWR would rise slightly from the tuning at ground level.

By Saturday evening I had adjusted all the tuning, secured the ties and finally waterproofed the junction box, I hadn't needed to do this before because this antenna had only been set up in my attic, So by Sunday morning the G3TXQ was ready for mounting

I grabbed the ladder, lowered the 40ft mast and removed the old G3TPW cobweb, I’d forgotten just how heavy the antenna is and it took a while to gently bring it down the ladder back to mother earth.

Placing the two antennas side by side it was interesting to see the physical difference. The G3TXQ is so much lighter; certainly the single wire and smaller aluminium central clamps make all the difference. 

The G3TPW has a much heavier clamp and is beginning to look very worn!

The G3TXQ is a much neater and lighter clamp, a definite improvement.

I also needed to do a few adjustments to the mast, add some more kevlar cord guides and do some general maintenance. Once that had been completed I grabbed the G3TXQ and hoisted it up the ladder and clamped it to the top of the mast, I have to admit it was so much easier than with the G3TPW and just looked a lot tidier! 

The final result and there was a definite improvement in performance.

By the afternoon it was all finished and after a quick SWR check I called a CQ and got another Russian Station (Alex R3ZK in Belgorod) who gave me a another 599, I was very pleased with the final results. 

There’s a few little bits I need to do, (like add the top mast clamp cover which I forgot.....doh!) But everything went pretty well according to plan and I shall now dismantled the G3TPW and store it away in the attic until I have another mad moment!

Final SWR results for the G3TXQ:

20 meters   1:2:1
17 meters   1:1
15 meters   1:1
12 meters   1:1
10 meters   1:1

Monday, February 17, 2014

Simple Magnectic Loop Antenna

A while back I mentioned my interest in mag loops and proposed at some stage to build an experimental antenna. 
After much searching I finally found and purchased a variable capacitor from my local radio club, I’m not sure of the exact tuning range but I figure it’s got to be approximately 20 -115pf, this should cover me for QRP work, but it obviously limits my power output. 

So now having the copper piping and the variable capacitor I’ve been able to begin building the antenna. As this is purely an experimental project I wasn’t going to make it as neat and tidy as some of the examples I’ve seen on the web. The idea was to build a simple loop connect it all up and see what happens. 

The first issue I had to work out was how to build it, as I had no experience with mag loops what so ever! But after hunting around on the internet I found plenty of examples and a handy calculator tool  to work out dimensions etc.

Getting round bending 9ft x3/4” of copper tubing was a bit of a problem, I had no plumbing tools so I had to have a think as to what I could substitute and eventually used my circular garden water butt which at roughly 3ft in diameter and set against a wall allowed me to squeeze the copper tubing in between the butt and the wall and gently pull the tubing in to a rough circle. It’s by no means perfect but as long as it circular I wasn’t too bothered. 

 It's not exactly round but it will do the job for this experiment!

For the smaller loop (Primary coupling), I used some thinner copper tubing measured length at 1/5th of the size of the larger loop and ¼” width, I could have used the same width tubing but as I had some of the ¼” handy and it was far easier to bend, I didn’t think that for this particular project it would cause any problems. 

The smaller loop threaded through the PVC tubing and ready to be connected to the coax.

Next I mounted both loops on an old piece of 7ft x 1 1/2” plastic tube.  Both copper loops were fed through holes I drilled midway along the length of the plastic piping so that they were held in place. The top ends of the larger loop were then attached with two pieces of thick copper wire and then soldered to the two connections of the variable capacitor. 

 The Variable capacitor connected up to each end of the main tubing

The smaller loop with both loose ends hanging down were also connected by thick copper wire and then via a choc block connected up to the coax cable which in turn is connected to the receiver or transmitter. 

Basically the whole set up is as simple as possible and took all of one day to complete. 

So, results – well I have to say I haven’t transmitted yet but I connected the mag loop up to my OHR100A and had the antenna sitting next to me as I tuned around 20 meters. No question about it as I tuned and peaked the variable capacitor the signals started coming in, it was working! 

Obviously I've got to do some more testing especially having a go at transmitting but so far considering I've never built a mag loop before I'm very pleased.

Tuesday, January 7, 2014

Heavy Weight K2 Tuning Knob

I recently bought the heavyweight tuning knob for the K2 off Ebay from a Bulgarian supplier. I’ve seen these tuning knobs before either on Ebay or via other Internet suppliers and have been staggered by the price, as much as £60.00. 

This Bulgarian supplier had the dial priced at £36.00 with free postage which I thought wasn’t too bad and so went ahead and purchased. The knob duly arrived well packaged and protected by a foam surround and a thoughtful inclusion of the required allen key. 

First impression of the knob was a well-constructed nice weighty item and I was keen to mount it on the K2 as quickly as possible, but imagine my disappointment when I offered up the dial and no matter how much I pushed it didn’t fit. 

I checked the dimensions, specifically the width which was 6mm but on checking the shaft width on my K2 it was more like 6.2mm!  I checked for any dirt etc within the knob or on the shaft but all was clean; there was clearly a measurement issue somewhere.   
Had I missed something in the small print?   

However the difference was so small all that was required was a 6.5mm drill and a steady hand and I gently removed some excess metal and hey presto the knob fitted neatly over the shaft.A little extra bonus was that the old K2 knob fitted perfectly on to my OHR 100A!

Anyway, I wrote to the supplier asking him if he knew that maybe Elecraft later versions of the K2 had possibly changed the shaft size. "Boris" kindly wrote back and indeed Elecraft had changed the shaft size somewhere along the 7xxx version, he had mentioned it in the small print but of course I had missed it, Doh! 
Never mind all is now well and Boris will make the small print a little larger for dumb people like me!

Tuesday, November 5, 2013

Repairs to the Mast

The autumn gales have now arrived and after a good summer you sometimes forget how bad the winds can blow round the Cotswold’s. When these gales appear I regularly lower the mast, the cobweb can easily be damaged in the strong wind, so I don’t take the risk and besides it’s fairly easy to drop the mast height and tie everything down.  

Last week we had a really big storm with wind speeds up to 80mph. Thankfully there was no real damage but when lowering the mast in preparation for the storm I noticed one of the collars looked a bit suspect and unfortunately when raising it back up the collar gave way and screw lever broke off. You can see in the pictures where it broke, the rust is a bit of a giveaway!

The broken collar

This particular mast is from a company called Radioizing, it’s 40ft in length and fully retractable, with an all metal design it’s quite sturdy and for the price was a good deal when I bought it some years ago. 

Wear and tear is beginning to take its toll and there looks to be a design weakness in the collars. To replace the broken collar all accessories have to be taken off so I have brought the mast down and obviously removed the cobweb at the same time.

The next collar up (as it should be) but look at the rust!

I’ve ordered a new collar so will have to wait for the replacement before rebuilding and then erecting it back up. But this will also give me a chance to do a quick service of the cobweb. 

The mast laid full stretch but collarless!

The other possibility is to switch cobwebs, by taking the G3TXQ from the attic and see how it performs, it’s also a much lighter antenna so it would be easier to place on top of the mast. I'm not sure how much power the G3TXQ can take compared to the G3TWP, I've easily had 400 watts out, which is useful for the DX, I've got a feeling the G3TXQ is limited to about 200 watts but I'll do some checks. 

 The G3TWP looking a bit lost!

The G3TWP could then be placed back in the attic which might prove an interesting experiment. But until I get the replacement collar there is little I can do, so for the moment I just have to wait.

Friday, June 28, 2013

Magnetic Loops

Time for another antenna project I think, but what to build?
Rummaging around the shed in the garden I noticed I have two 12' copper pipes roughly 1/2 inch diameter that have been sitting doing nothing for a number of years. Since they are not needed for plumbing I’m sure I can put them to good use.
I was thinking about making a small magnetic loop antenna, the measurements seem pretty straight forward  but at the moment I have little knowledge about what variable capacitor will be required and how it’s all connected up. I guess it’s a matter of searching the net and see what I can find.
A quick search has revealed a lot of theory but nothing substantial on building. I prefer something with pictures and an easy explanation to all the “geeky stuff” (not that I’m against it) it’s just I like to see everything laid out in front of me and easy to follow.
If I could build a reasonably small antenna hopefully that would fit in the attic it could turn out to be a fun experiment. Anybody who has details or knows of a website with fairly easy instructions I would be “mucho grateful” if they could let me know. In the meantime I can get on and figure out what band I want to use and see about measuring up the copper pipes.

Monday, June 24, 2013

K2 Update Sunspots and Other Hobbies

Well it's been a while since I last wrote so I thought I'd better give an update with regard to what's happening in M0AUW radio land!

I've been playing a lot with the K2 getting to understand the different filter settings and the manual ATU settings. Setting up the correct filter settings is really important and can alter the operators outlook on how they perceive this wonderful radio. Mucking up the settings can make the receiver sound dull and noisy and you have to be very patient and thorough otherwise you may start wondering why everyone is saying it's such a good rig, when you find it, well, just ordinary!

But once you have spent the time getting everything right it really is a good little transceiver, the receive quality is outstanding certainly matching the old FT1000 MP V although I have to be honest for day to day use I still prefer the FT, I find it much simpler to work, probably because I don't have to mess about with manually adjusting the ATU.

I've learnt that it's not always good to have the preamp turned on, it does tend to raise the background noise. Finding a weak signal and then using the filters can bring up the signal without the need for the preamp, it is really down to just lots of practise and playing with different settings.

Contacts have been good but the DX has been appalling when you take in to consideration that this is meant to be the peak of the cycle, some days there's just nothing going on with regard to DX, unless of course you have a massive yagi sitting on your tower out in the garden! The cobweb is no slouch when it comes to DX nor is the 30m vertical I have but lately it's just been dead which is very disappointing. However I get by and am happy to be contacting various stations in and around Europe with the occassional DX thrown in.

I watched a very good programme on the BBC last night all about the sun It explained about sun spots and radiation patterns and also discussed about a much longer cycle (the 300 year cycle) and the possibilities that we maybe approaching another of these, one of their reasons being the change in the weather conditions over recent years, all very interesting stuff and well worth a view.

Thinking ahead I will definitely be upgrading the K2 to SSB and I have a contact who has the spare option so hopefully we can do a deal and I can install over the winter which will give me something to do.

In the meantime besides the radios I have other things to play with and am in the process of building a touring bicycle for my future attempt at riding the "end to end" run which is John O'Groats in Scotland to Lands Ends down in Cornwall, some 1000 odd miles riding.

I'm quite a keen cyclist not by any means a gung ho speedster but happy to do a 2 hour ride round the cotswolds on a Sunday morning which keeps me reasonably fit. The plan would be to cycle approximately 50 or 60 miles a day and take in the scenery of the English countryside at a reasonably steady pace.

But like all things it's finding the time (at least 10 free days) to carry out this little jaunt and working out where to stay and what route to take, maybe next year or possibly when retirement is looming!

What would be be even more fun it to do the cycle ride and have a mobile attachment on the bike, hmm could prove interesting!