Thursday, February 28, 2013

Supplier Of Litz, Litz, Litz And More Litz Wire For Sale

I just got in all my Litz Wire and have the re-spooling and coil winding machine done.
I have for sale the following sizes of Litz Wire. To my knowledge I have the largest selection of ready to buy Litz Wire I have seen. The larger sizes are sold in mutable 10 ft. lengths. However any lenght can be custom quoted. 

You can purchase at:

Or at my home page:

We have the following Litz Wire Supply.
16-38 Litz Wire
10/46 - Litz Wire
20/46 - Litz Wire
40/46 - Litz Wire
60/46 - Litz Wire
80/46 - Litz Wire
100/46 - Litz Wire
140/46 - Litz Wire
175/46 - Litz Wire
220/46 - Litz Wire
330/46 - Litz Wire
550/46 - Litz Wire
660/46 - Litz Wire
10-44 Litz Wire
20-44 Litz Wire
40-44 Litz Wire
60-44 Litz Wire
100-44 Litz Wire
140-44 Litz Wire
180-44 Litz Wire
220-44 Litz Wire
330-44 Litz Wire
420-44 Litz Wire
660-44 Litz Wire

The wire is of good quality, I have no way to test the "Q" of the wire so I sent some out and had it tested here is the results for the 660/44 Litz Wire.
42 turns on a styrene 4.5" coil form--with 10" pigtails, that's about 51.1 feet of wire (the coil measured 172 uH):

200kc 680 Q
300kc 890 Q
400kc 1050 Q
500kc 1160 Q
600kc 1268 Q
700k 1270 Q
800kc 1240 Q
900kc 1200 Q
1200kc 1030 Q
1400kc 905 Q
1600kc 770 Q
1700kc 683 Q

I am sure the smaller sizes will have lower "Q" but this gives a good idea of the quality of the wire in general.

Picture of 16/38 Litz Wire, Silk Covered.


Picture of 46 Awg Litz Wire, Nylon Covered in various colors. Shown are just a few.







Pictures of 44 AWG Litz Wire. This size is silk covered and the pictures represent the color of the wire.




You can purchase at:

Or at my home page:

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Wednesday, February 27, 2013

Radio Rallies


I attended my first radio rally of 2011 today. Held by the Swansea Amateur Radio Society at the Neath Sports centre.
This is not a particularly large rally but it seemed well attended and it was nice to meet up with some friends old and new. One of the highlights for me was meeting fellow blogger and local CW partner MW0IAN, Ian.
I came away from the rally with a few small items-a couple of BNC plugs, a dipole centre piece and some 300ohm feeder (I am thinking of making an HF doublet).
The next rally for me may be at the end of June (west of England Rally), these radio events are quite thin on the ground now, when I started in the hobby it seemed like there was a rally almost every other week!
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Tuesday, February 19, 2013

Wouxun KG- UV920R Dual Band Mobile Transceiver.

Wouxun the Chinese HT manufacturer announced and showcased their first dual band mobile transceiver recently, called the KG - UV920R. It is earmarked for general release around May of 2011 and is said to be the first dual band FM mobile receiver released by a Chinese manufacturer.

Reports say that it sports 50 watts on VHF and 40 watts on UHF and n fact it sports 3 ham bands on transceive (220MHz - if you are in the USA, not much use for the rest of the world except for RX). Other feature include dual receivers, cross band repeating fuctions, general coverage HF receive with AM and extended RX from 65MHz to 220 MHz - FM band (would cover FM bands overseas and in the US, and analog TV broadcast audio, if that still exists anywhere). RX also on LW and MW in AM. Rumor has it the cost will be in the range of US$140 - 200.



read more "Wouxun KG- UV920R Dual Band Mobile Transceiver."

ESmooth Ebony Wood ES-820EB Headphones.


I have purchase a nice set of ESmooth ES-820EB Ebony Wood headphones which fold up and are great for portable use on the go. Yes and the sound great. The headphone wiring is detachable which gives me the opportunity to upgrade the headphone cable.

Features:

Ebony wood housing
Powerful and deep bass, crisp high response.
Natural and warm sound re-produced due to real wood housing.
Passive noise isolation.
Works with iPhone, iPod, Blackberry, MP3/4, computer, CD players etc.

Technical Data:

Frequency response: 20Hz – 20KHz
Sensitivity: 113+/-3dB At 1KHz1mW
Impedance: 40 Ohm
R&L balance<>


ESmooth ES-820EB Site

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A "Doing" Day (in the shed)

A few days ago a Skype message from one of my small group of "Skypees" alerted me to the fact that an equipment failure had occurred. Jim's 30 amp power supply was no more. I was being asked what I thought about a couple of possible replacements, but as I enjoy the challenge of "fixing things", and also generally far too parsimonious to countenance replacing something old with something new without at least putting up a fight, the Skype conversation quickly got round to the faulty equipment and to what might be wrong with it.

With almost astonishing speed I was appraised of fault symptoms and then a copy of the circuit diagram. It was completely dead. Nothing coming out of it, apparently. Nil. Zip. Nada. Not even "magic smoke".

The circuit diagram was examined and I figured out some likely causes, all which seemed to be fairly straightforward to resolve, and so it was arranged that I would call in to see my friend when I was passing his home a few days later.

In the meantime, my friend proceeded to purchase a replacement unit (a hundred pounds, near as dammit!) and was very pleased with it.

The broken power supply was duly collected yesterday afternoon, and today I decided to take a look at it.

The power supply is called a "Nissei DPS-300GL" and is quite a hefty beast. Opening it up I found it to be quite nicely constructed, albeit rather grubby as the cooling fan had been dragging unfiltered air in and across the internal heatsink for many an hour. However, no matter what the outcome of my efforts was, the fan would drag no more air as it was completely seized up beyond redemption.





Inside the Nissei PSU (quite neat isn't it?)


My earlier deliberations had led me to suspect a problem with the overvoltage circuit, but I adopted a technique I have used on many occasions to prove or otherwise the general health of power supplies, and that was to connect a current limited supply at the correct DC voltage across the main rectifier output. Encouragingly this brought the majority of the power supply to life, at the same time lending weight to my original theory about the overvoltage tripping circuit which was fed from a completely separate supply via its own transformer.

Next I moved the external supply to the rectifier in the overvoltage circuit, and to my slight surprise the "enabling" relay (the overvoltage trip drops out the relay which removes the AC mains supply to the main power supply transformer) was heard to operate. My original theory was that there was a fault with this relay, or its associated driving circuitry.

Fortunately this piece of circuitry is built on its own separate board and was relatively easy to extract and examine.

It didn't take long with an eye-glass and a multimeter to get to the root cause of the problem - see the attached photograph.



Underneath the Overvoltage Board ...

A nasty looking joint at the relay contact which switches the AC mains to the main part of the power supply. Bingo!

The joint was cleaned up and resoldered, the overvoltage circuit returned to its rightful place, the PSU powered up from its own mains supply, and lo and behold the PSU is now working, albeit temporarily without a cooling fan.   I realised at this point that the description of the original fault symptoms must have been slightly wrong in that the trip relay would have been heard to operate upon the application of mains, and I didn't verify this myself. Having said that this might have made me more worried about what the cause of the fault was!

Having spent a few frustrating minutes wrestling with Maplin's web site looking for a replacement,  EBay was consulted, and a 92mm 12V DC fan was quickly found and has been ordered for the princely sum of £4.99 (including postage!).

Soon Jim will have a spare power supply.

Right!  On with the next job ...

Today is the day I finally decided to start building my "X-lock", a VFO stabiliser kit from local firm Cumbria Designs.   I've had this "in stash" for quite a while as other projects have got in the way.  Once built I have then to decide which rig of my various"old ladies" will get the benefit.  At the time of writing I think it will be my FT-107, but that is by no means certain.   I also have it in the back of my mind to build the version described by Eamon Skelton EI9GQ which seems to be a variation upon the same theme.   Still, that will be a way off as I still have to "cut my teeth" properly with PIC programming, another medium-term objective of mine.  It will be interesting comparing the performance of the two units, and the advantage of the EI9GQ version is that the PIC source code is in the public domain, and I would have the opportunity to experiment with it.



X-Lock construction under way

Anyhow construction of the X-lock has now commenced, hopefully it can be finished off tomorrow, with luck.
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Monday, February 18, 2013

Deep Joy! A New (to me) source of meteor pings!

Tonight, courtesty of a link I found on Andy Smith's excellent TVCOMM web site, a really good list of current Band I (and other) frequencies in use, one of which is used by the Czech Republic. The transmitter is located near Ostrava, and runs at 100kW ERP.

I reckoned this to be a good distance for meteor reflections, so I tuned in my receiver and listened for a while, and, yes, I thought I heard the sound of meteor activity.

On came the software to track it down (first Spectrum Laboratory for a wide sweep, and then R_Meteor for a narrower sweep centred on a 1kHz beat note), and, yes, the unmistakable traces of meteors.




Now for the bad news - according to the link I referred to, this transmitter closes this November. But until then, I well keep looking!

The frequency I am monitoring, in case you are interested is 49.75949MHz, on my FT-920 which does not have any kind of precision frequency standard, just usual bog-standard crystal reference for the synthesiser. (Don't forget, this is offset from the "true" frequency by 1kHz so that the audio spectrum analyser based software works properly)

As you can see from the image above, I am getting LOTS of pings.
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Update

My confidence in CW operating is slowly improving. As well as a couple of QSOs with local amateur MW0IAN I have also managed a QSO on 80 metres CW with 2E0ROD in Peterborough. This evening I have some time in the shack and I was going to try a few CQ calls. Switching on the HF rig however I was met with S9 of noise over most of the HF spectrum. Lets hope it is only Temporary, it sounds like some localised electrical QRM.
As an extra incentive to improve my CW I have joined the FISTS club. Their website can be found here.

Because I have been concentrating on CW I have not been on the air on PSK31 for some time now, this was a mode which I was using quite heavily up until now. Whilst I am sure I will return to the data modes it is nice sometimes to be able to operate the radio without having a PC switched on. Maybe thats why I am not really interested in SDR at the moment. I have however been using a borrowed "Softrock" SDR receiver connected to the IF output of my TS830 to monitor the CW section of the bands and I find it very useful.
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Sunday, February 17, 2013

I - Mego Retro Heavy Beats Headphones

I don't seem to have much time to myself these days, so don't have much time to do a full review of these headphones. But I was impressed by the build (no flimsy build here) and the audio quality, so I just had to make a short posting here for people who may not have heard of them. Check them out, take them for a test and you will be happy you did. The I-Mego Retro Classics Heavy Beats Headphones resemble the old Shure microphones Elvis used back in the 50′s. Very Stylish.

The Retro headphones are I-Mego’s range-topping line (sold for about $70) currently consisting of three models: Classic (chrome/white) mainly meant for human, vocal, new age and classical music and Heavy Beats (brown/gun metal) meant for R&B, Hip hop and rock, and a new red version for full range articulation which has just been released.

I-Mego Home Page


Driver Unit 2 X Ø40mm

Frequency Resp 20-20KHz

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Saturday, February 9, 2013

Ongoing project

The receiver pictured is a Realistic DX150A. Its a general coverage receiver from the late 1960's/Early 1970s. It is a simple, single conversion analogue set covering from Medium wave up to 30 Mhz. I bought it on Ebay as a "spares or repair/not working". Externally the receiver is complete and in good condition although it was quite dirty!
When it arrived here I connected it up to a 12 volt supply and was surprised to find it does work! It does however need quite a bit of attention, there is a broken tuning core inside and the BFO does not work so it only receives AM at the moment. The receiver has been modified in the past. You may be able to see the two BNC sockets on the rear. One of the BNCs is for an antenna, the other, well I'm not sure but I think the receiver may have been modified to take a digital frequency counter.


I haven't tried to connect the receiver to the mains supply yet. For one reason it has an unusual connector for the AC lead (I think this may be another modification) secondly there is a possibility that the transformer may be for a 110v USA type supply. I have a friend who has a variac and one I have sourced a mains connector we may be able to see what the correct operating voltage is using that.

I am hoping that trying at least to improve the receiver will result in some fun and some learning along the way.
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Sunday, February 3, 2013

First Step in CW

Fellow blogger and local Radio amateur MW0IAN drew my attention to a range of frequencies around 3570 on 80 metres where slow(ish) CW QSOs were to be found. I set up my TS830s this evening on that frequency and was monitoring when I heard a very strong station calling CQ. It was none other than MW0IAN himself! Well I had no excuse, he was sending at a speed I could read, nice clear CW and a strong signal. I had to reply. We had a short but enjoyable CW QSO, my first on that mode for over 20 years!
I felt it was a step in the right direction, I will be a little less nervous with my next contact on the key now that I have broken the ice so to speak
Pictured below is my CW station. Note the straight key- I need quite a bit more practice before I consider using the paddle.

Anyway thanks Ian for the contact, i don't suppose we broke any DX records- probably no more than 1km between us-but it certainly helped my CW progress.
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