uMy trusty Icom IC-7400 had recently an intermittent backlight for a few weeks then finally failed...
Google searches produced a number of results but the most promising was at https://iz0egm.jimdofree.com/repairs-or-mods/icom-7400/
It became apparent that this is a common issue with several models that presumably use the same or similar circuitry.
In due course I opened up the 7400, took off the front panel assembly, disassembled that to get down to the area on the PCB where the backlight inverter was and, sure enough, the 2SB1202/Q302 (on logic unit) was discoloured as was the PCB around it. I used a heat gun to remove Q302 and even the adjacent PCB was showing signs of heat stress. I doubted that I could cleanly install another SMD power transistor.
I wasn't going to buy a "backlight repair kit" at an inflated price from eBay and I have lots of bits on hand so I replaced the 10uF electro (C302) with a standard single-ended leaded type, the 47uF (C303) was replaced with a low-ESR standard leaded variety. The replacement for Q302 - that 2SB1202 - opened up a few issues due to parts non-availability. The IZ0 article mentioned a BDX54C as an alternative but these days even those aren't available. You have to remember that many semis are no longer manufactured due to changes in appliances' manufacturing techniques, so it becomes a matter of cross-checking data sheets as well as suppliers' product availabilities..
I finally settled on a TIP42C TO-220 style PNP transistor, drilled a hole through the side of the tinplate shield, used a flat insulating washer plus a nylon isulator that the 3mm screw passed though and then retained with a nut inside the tinplate box. Oh, and did I mention that I used heat transfer silicon grease between the insulating washer and the back of the TIP42C and the washer and again between the washer and the tinplate. This process allows the large surface area of the tinplate box to act as a large (though thin) metal heatsink. The 'B-C-E' leads were jumpered across to the PCB pads with short lengths of single-strand copper wire.
So, in effect I did the IZ0EGM repair - but without using SMD parts.
The result was that I now have the 7400 with a functioning backlight.
I am in need of a calibration service for my Bird 4410 and 4 elements. I just got a quote from Vicom and it is disgusting to say the least. They want 3 times the cost in the US for the 4410 and double for the elements. Plus they put a $390.00 assessment fee onto the quote! At that rate it would pay to send it home!
Are there any amateurs out there who know the procedure and can give me some hints? Or direct me to someone who can help?
The age of video sharing only highlights the way the USA has corrupted the English language, one of my pet hates is how 'solder' is officially pronounced in the USA as 'sodder' but they still say 'welder' as welder and not 'wedder' as I would have expected.
There must be a 100 of these quirks but every time I hear a USA Ham say 'sodder' I cringe and they go down one step in my estimation of intelligence.
I do not want to steal other peoples thunder by do you have others to add to this list?
We are pleased to announce that Release Candidate WSJT-X 2.7.0-rc4 is ready for download and use by beta testers.
WSJT-X 2.7.0 Release Candidate 4 includes new features (especially for companion program QMAP) as well as bug fixes. A full list of enhancements can be found in the Release Notes:
Release Candidates are intended for beta testers. If you download and use WSJT-X 2.7.0-rc4, please remember to provide feedback to us on the new features in version 2.7, and on anything that does not seem to work properly for you.
Direct links to installation packages for Windows, Linux, and macOS can be found on the WSJT-X page https://wsjt.sourceforge.io/wsjtx.html Scroll down to the heading "Candidate release: WSJT-X 2.7.0-rc4".
For those who like to compile from source, a complete source-code tarball is available at the WSJT-X page. Public access to the git repository for the WSJT project is also available on the "Git" tab here: https://sourceforge.net/projects/wsjt/
It may take a short time for the code to be updated on SourceForge.
WSJT-X is licensed under the terms of Version 3 of the GNU General Public License (GPL). Development of this software is a cooperative project to which many amateur radio operators have contributed. If you use our code, please have the courtesy to let us know about it. If you find bugs or make improvements to the code, please report them to us in a timely fashion.
The authors and Copyright holders of WSJT-X request that derivative works should not publish programs based on features in WSJT-X before those features are made available in a General Availability (GA) release of WSJT-X. We will cease making public Release Candidate (RC) pre-releases for testing and user early access purposes if this request is ignored.
Feedback should be sent to this email list or one of the of the others mentioned here in the User Guide:
After a hiatus caused initially by the NBN, the interruptions of Covid, moving interstate, making the new house liveable, learning to enjoy the new surroundings, coping with an awful project at work (you know, life stuff) I have dusted off some of the gear and started cobbling a temporary (for now) station together.
Our block has a largish veggie garden that has a metal frame over it with a shade cloth cover. Methinks that as an interim solution to overcome the analysis paralysis of what real antenna/s to put up, I will bung a bit of angle onto the frame, whack on a delrin base and stick my FAMPARC multi-tap helical whip and run some coax across the yard to it.
As I wasn't too fussed and the VSWR was within reasonable limits that the tuner could handle - I looked no further.
I got the radio and interfaces up and running. Lo and behold I was getting decodes on FT8 immediately. I spent a couple of evenings trying the break the duck on my VK5 callsign.
No luck. Plenty of decodes and PSKInfo said I was being heard and decoded all over the place.
Early this morning, about an hour before the sun it was over 25°C so I got up and started mucking around on 20m FT8 again. "Hang the expense, I'll do a quick tune of the helical" I said to no one in particular.
Broke out the VK5JST analyser, yup it still works so off I go to tune this thing. Back and forth, up and down the ladder, you know the drill. From one end of the adjustment to the other. Best I could do was 2.63:1.
Seems odd to me.
Once the sun had risen and I could see more clearly I decided further investigate the groundplane/veggie garden sun shade. It is all 40x20mm gal section in a grid, held up by treated pine posts. I grabbed a DMM and started to check continuity amongst the frame members.
Mostly good. Except the cross member I had chosen to attached to. It must have been an afterthought, added for bracing. It is screwed to the pine uprights, but air gapped where it passes the other metalwork. To quote Adam Savage from Mythbusters "There's your problem". The groundplane was a single 40x20mm gal section about 3 metres long.
The VK3RTV Tuesday 8pm net also livestreams to YouTube every week via Ian VK3QL’s YouTube channel. It goes for about an hour or so each Tuesday night and is very interesting… https://www.youtube.com/@IanVK3QL/streams if you can’t receive it direct from the VK3RTV repeater at Mt View in Glen Waverley.
More info here… http://www.vk3rtv.com/ the VK3RTV system has almost been a full time job by Peter VK3BFG to keep it going for everyone to enjoy. Feel free to contact Peter if you’re interested in a donation to help keep the wheels turning.
Of late, there’s been a bit of chatter & video of what a few stations (from the IC-905 club) are up to with their microwave projects & operations.
In particular, last night Mick VK3CH showed some ideas that he got from Andrew VK3FS in regards to a pan & tilt mechanism for his 10GHz system. Go to last nights livestream here https://www.youtube.com/watch?v=k5lE2aACIXs and scroll forward to 24min30sec for Mick’s presentation. It’s great to see some more stations building microwave gear for the rest of us to work.
In case you’ve lost it or haven’t seen it, attached is a 2024 MAD calendar, created by Scott VK4CZ.
The next opportunity might be the John Moyle Field Day weekend on the 16th/17th March which is the same weekend of the Train & Hobby show at Sandown that a few stations will be operating/displaying at. Whilst I’ve got a family function that weekend, I should be able to sneak out for a few hours on the Saturday arvo. I’ll hopefully have my **** together on the 439 liaison radio front and some slightly better feedlines for my 2.4 & 5.7 have arrived today from VK5 which should improve things slightly by a poofteenth.
To give everyone, including the Gippslanders, a better chance to get amongst it, what time would most people be likely to head out to start? Say 1pm or 2pm until early evening, in case the DX conditions improve in the early evening? Keeping in mind that it’s a bit of a drive for some people to get to their favourite hilltop location. I’ve had a quick look at the 14 day WX forecast and that weekend looks fine, thus far. I’m not sure where I’ll go yet, but likely to be Mt Buninyong, especially if the predicted rayline plots to Mt Tassie look good. I’m guessing, for at least us Westies, we’ll have a few out and about, including west of Bacchus Marsh, west of Geelong, south of Ballarat and possibly the Bellarine Peninsula. I’m guessing that a Horsham station might again be operating from One Tree Hill Ararat. Early evening often seems to be the go looking towards VK5.
Don't forget to post your location on the Contest Radar Contest Radar
According to recent reports, the AREG or Adelaide Radio Experimenters Group and having a radio & electronics sale on Sat 26th October.
I’m quite sure I’ll be going, hopefully for at least a few days, possibly making a week of it. Maybe a few nights in Hahndorf and maybe a few around Glenelg down by the beach. I was going to take along my uWave gear, etc and maybe rattle the cage of a few VK5’s who might be interested in some microwave activity sessions. Is anyone else interested in doing similar??
If anyone is interested in such a road trip with some MAD sessions with the VK5’s, email me direct nikp007@bigpond.com and I’ll get the ball rolling, sort out some accommodation, set up some contacts and a rough programme. My vehicle will be chockas and no spare seats. I was thinking Hahndorf for the first few days as it’s up in the hills and Paul VK5PAS lives in the area I think – it’d be great to have him out for dinner one night. Then maybe a couple of nights around Adelaide somewhere to maybe arrange a dinner with a few local VK5 microwavers one night as well. Plus there’s a few traps around VK5 such as the many wineries…
If you cannot access the forum any more then it could be that your IP range has been blocked as part of an approach to keep out a recent steady stream of Russian hackers.. Unfortunately other valid users might get blocked also but there is little can be done about that.
One Russian hacker did make it through last week, had a post accessable for about 3 hours and posted just once, part in English and part in Russian. Since then, the server access logs have been reviewed and any IP address range seen to be a viable hacker access point has been blocked. This is being reviewed daily and more new address blocks are excluded each time checked.
If you have been blocked then the only way an unblock will occur is if you directly email me your IP address and user name and I will check the user log.
I will NOT unblock IPs that are from VPNs.
If you don't know how to email me then you need to do a bit of research !
Saturday 6th April at St Michael’s College, The Abbey Place, Caboolture.
Hi,
It’s John Saunders (VK4BZ) from the Redcliffe and Districts Radio Club.
This year’s Redfest is doing things a little differently!
Ladies! We are trying to look after the ladies in our lives as well as the ladies on-air with their own callsigns. As such, Redfest 2024 will feature non-radio related tables focussed purely on female interest areas. There will also be a specialty café with proper coffees, cakes, slices and cookies, along with sit-down café tables under the club marquee. Very civilized! ALARA will also have a presence this year to encourage more ladies to take up this great hobby of ours. So, invite the ladies along this year! (My XYL is coming!)
Technical! For those who want to expand their technical knowledge, there will be a demonstration of the ICOM IC-905, the new commercially made microwave transceiver. The Brisbane VHF Group will also be there to do a Tech Talk on microwave propagation.
Prizes! Raffle prizes are always attractive items at Redfest and this year is even better with the ICOM ID-5100A VHF/UHF FM and digital transceiver as the main prize. There will also be minor prizes as well as hourly lucky door draws.
And as usual! Yes, all your favourite stalls full of pre-loved goodies along with our regular commercial sellers will be there too! Did I mention Dougie’s famous bacon and egg rolls? Yep, the BBQ will be running hot as always.
Food available from 8:00am and the gates are open to the bargains from 9:00am. Major prize draw is at 11:00am. Entry is $5.00 and raffle tickets are also $5.00 (can be purchased prior to the day – see the club website).