Contests - Bah Humbug !!! Thank goodness for 17M

Spent some time yesterday and today pottering in the shack, working on one of my eBay purchases (have taken some before photo's so might write it up when I get a chance! either way a good news story its up and working again, simple fix thankfully, now some cleaning and further tidying up is needed), and I had the FT-1000D on as usual.

Totally forgot that it was the CQ WW WPX Contest over this weekend. For those that don't know this is a marathon worldwide contest run by CQ Magazine -  (and I do mean marathon) SSB contest over two full days, with many sections both Multi and Single Operator, high power (1.5Kw where allowed!!!) all the way down to QRP (5w).

Now let start by saying (classic :) ) - I don't hate contests (in fact I won the 2012 PW 70Mhz low power contest operating portable), BUT what a total mess !!!

40M was wall to wall contesters ( and I do mean wall to wall I checked stations from 7.045Mhz all the way up to 7.199Mhz)  - firstly my radio's are properly calibrated and so the station operating on the latter frequency was surely operating out of band ? (assuming a bandwidth of just 1.5Khz which is a little low) then he was out of band - thus illegal (this was a DL station) the lower edge was right down in the digital area and whilst not illegal didn't really keep up the spirit of the bandplans (This was HB station). Some we really badly overdriven with poor audio and over compressed audio giving rise to wide signals (and no it wasn't my front end being overloaded!) the worst was over 6K wide - this one was so bad I had to put it on a bandscope as I couldn't believe it...... it really was that wide!!!

I did give away a few multipliers to UK stations earlier today, and a few US stations when I could hear them this morning.

I couldn't listen to the RSGB news broadcast on 7.150 Mhz , not the end of the world, and I did manage to work an couple of non contest stations but anyone wanting to do something not related to a contest had to migrate to a WARC Band.

This I did onto 17M and what a difference, yes some "your 59 73's" type contacts, but a longer chat with the states, and some nordic contacts and across into Spain and Greece what a breath of fresh air !!! 

Now I'm a very competitive person but think to effectively shut down 40M / 20M for basically two days over this weekend is a little much. I, for the first time ever, felt sorry for a station (actually a UK amateur living in Germany) who was trying for a solid half an hour or so to get a contact at the top end of the band (no not the one above who was out of band !) he was called by people asking for his serial number etci. time and time again, I tried to go back to him but the contest QRM was so bad we couldn't make it. He like others simply gave up.

I'm sure he wasn't alone, I must be getting old.......

48 Hours is a little much in my opinion 24 hours yes 48 no.

Just me ? 

Probably it is !!! -  mutters as he walks off with a bottle wine grumbling to himself :)

Bringing an Ameritron AL-811HXCE back to life - part 2

So you will recall that this 811HXCE has been badly overheated (to say the least).

I'm pretty experienced on valve amps, grounded grids et al, but i've not ever worked on one of these.

So some internet searching and come up with some nice information and background. I've joined the Ameritron yahoo group (here) (really worth doing a wealth of detail and experience on there) - Also came across a site from a German ham (DC9ZP) who carried out a review (in German) of this sort of amp and had carried out some upgrades (several of which I had planned myself such as a glitch resistor and upgrade HV caps) this site is here.

It really nice that someone has worked and upgraded these before (and thank goodness for google translate!!).

Further research also turned up the guy that designed these for Ameritron and Heatkit - thats Bill  - W8JI.

He has a great deal of stuff about valve amps its a real resource and I strongly suggest if your into this stuff have a look - its here with the specific detail on the 811 series here. It really is great if you (like me) like this stuff !! :)

So I got to thinking about the plate choke (it was burnt out see my previous post) - I Could simply get the parts from the states (UK dealers don't apparently 'hold' spares - difficult to believe i know !!) I priced them up and whilst they are quite low cost (coil at about $30, parasitic board at about $45) the cost of shipping and import duties / VAT would push it up to over £150 - a bit pricey and nearly 2/3rds of what I paid for the amp !

Or I could rebuild them - so I decided to rebuild them (well if they don't work I can also stump up the money !!) - W8JI has a great section on his site about plate chokes (he actually has a picture of one of the ones used in the Ameritron amps !) - here - This gave me the confidence to use the former and wind a replacement - so next post will detail this.

My plans are basically 

1. Work out the wire gauge
2. Mark the former really carefully with where the wire should be (including the gaps !)
3. Count the windings really carefully (at least three times!!)
4. Unwind it (counting the turns to check my counting was right!)
5. Wind on the new wire
6. Seal carefully
7. Measure its resonances using miniVNA

Onwards and upwards !!!!

Wow - Aruba on 17M

Wow - just worked P40Z (Oliver) in Aruba on 17M - not too shabby for a wire Delta loop, was your usual 59 / 59 type qso but I'm still pleased with it :)

For those of you that don't know where Aruba is - Aruba on QRZ.com its off the coast of Venezuela  

Bringing an Ameritron AL-811HXCE back to life

I found this unwanted and unloved on eBay. It was sold as faulty with the comment in the description " I've tested it by turning it on and can confirm that the meter reads 1700 volts, i've removed the valves as the anode caps have come off, other than that in excellent condition"

Mmmm interesting especially the last bit anyway, thought it worth a punt / set my limit fired up my sniping software and waited. I won it for a good price (considering these are priced new at around £900-£1000) , and decided to pick it up. Anyone who doesn't pick a unit like this up themselves is asking for trouble in my opinion !!

Got it home and then left it for several weeks - work etc.

I have some very simple rules when testing any equipment I buy - unless I know (and trust!) the person i've brought it from - I never plug it in without a very careful internal examination and safety check - old(er) equipment gets extra special treatment - when I write up one of those I will detail what I do.

Anywhere here it is on the bench (forgive the mess!!) - 



As you (hopefully!) can see its in pretty good nick really, looks hardly used, all the knobs works really smoothly with quite a satisfying 'clunk' on the band switch.....

So obeying my rules (however tempting!) I opened it up and ...... boy was I glad, in fact I was amazed that the seller didn't damage himself permanently (perhaps fatally!).

(Left) - This doesn't look too bad does it ?
However have a closer look (there are no valves these were removed by the seller as the anode's of the valves had 'fallen' off) the white 'things' hanging down are the ceramic caps that should connect to them (there are 4 valves in total) the other two are just to the right of the centre of the picture. If you look closely the board that these connect to (actually the parasitic board) looks a dark colour - perhaps a clue here ? and the coil below looks a little odd as well doesn't it ?

Here is a picture (Right) that shows a close up of the board (with the coil below it) as you can see the board has been badly overheated (and I mean badly!!) . If you look really closely the coil below is also very dark, and if you look really carefully you will see that the coil has got so hot that it has actually melted the coil winding making it open circuit !!! - you can also see the braid connecting from the parasitic board to the anode ceramic cap had also been blackened very badly. Wow !! now you can see why I'm glad I have my checking routine as without it I am not entirely sure what would have happened, probably (as per the seller) nothing too bad, HV (1.7Kv) would have been generated but wouldn't have gone anywhere as the coil is open circuit (and of course no valves !!).

Anyway here's a close up of the coil you can see the damage that has been caused by the overheating. One can only speculate what has caused this overheating.

I've worked on many valve amplifiers with many / varied faults but I've never seen one this badly damaged by heat / overloading. It doesn't look like a result of bad tuning (there are no signs of arcing anywhere) it simply looks like one of its previous owners has loaded it up in a mode with a high duty cycle - Digital / PSK or RTTY perhaps, maybe CW in a contest - at the maximum output power and gone for it !!!

And then done it again and again and again (maybe !!) - either way it needed some work - urgently !!! - I decide to give it a more detail electrical and electronic check, and with the exception of one capacitor in the meter circuit, all were good, no signs of any damage or arcing in any of the usual places (plate / load capacitors). inductors etc. 

From the date stickers looks like a early 2009 example, so not too old at all.

So time to do some digging on the net and see what I can find, these are popular amplifiers in the US, with quite a good following, reviews vary but treated well will do well over the UK legal limit without breaking sweat. Looks like I will need to get / make a new parasitic PCB and anode coil at least, I also plan to add some of my standard upgrades such as a glitch resistor and upgrade the HV Caps if I can find some decent examples.

More on this one to come :)

Well here goes !!!

Well here goes !!! - Thought I would start a blog to record my adventures in radio especially the repair and reviving of transceiver's that I have collected or gained via various forms (mostly eBay!) - trying to recapture all the things I wanted to own as a I grew up !! you know Heathkit - Ten Tec - Yaesu - all those things you couldn't afford early life, then families and responsibilities come along.......

A little background first - 

I have been interested in how things work for as long as I can remember, and so I guess it was a natural thing when I asked my parents how radio worked. They in desperation sent me next door (how lucky was that !) to a wonderful radio ham called Fred (G3YMQ as I recall, now SK) who was remarkably patient and understanding. He let me use his radio's to listen to all those places far away (I remember the day he purchased an FT-101ZD) and we set it up together, simply wonderful.

Thanks to his patience and encouragement I got really interested in electronics and this led me to a career, via the Civil Aviation Authority training at Bletchley Park (yes enigma an all that) I lived there for two years or so really learning about electronics, radio, then posted to Heathrow airport, then a while later to get into management and 27 years or so (!) later via electronic design, firmware, computers, service management, WAN design, BPO, IT Security into (currently) the Senior Civil Service, working at - well don't think I'll go that far just yet - we hardly know each other !!!

Anyway - I have many projects on the go so I will start to list them over the next few weeks and hopefully record and provide some useful notes on the approaches I used to bring them back to life again !!!

I'm also pretty active on HF from home (at the weekends as i'm pretty bust during the week) - (mostly 7Mhz / 17Mhz / 50 Mhz / 70 Mhz + 2M + 70CM) and so might post on that activity as well as my plans for a new mast I'm planning and my HF antenna experiments.

73's for the moment - M1ABK

PS - Just noticed I've won something new on eBay - bet you can't wait !