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Fail to prepare #2


#1

When I was in France the other week I preempted an imminent SOTA equipment failure. One of my antennas uses a small loading coil, or two coils in series with a shorting link attached by crocodile clips. Both coils for 30m, the small coil for 20m and no coils for 17-10m. Anyway one of the fly leads, made from the shielding of RG58 flattened was breaking up. I was able to borrow a large soldering iron from my brother-in-law such that I could bodge a repair which held for the rest of the expedition.

So yesterday, I removed the old fly-leads and made some new ones out of an off-cut of some wonderful Teflon insulated multi-stranded silver-plated cable. This is kink free and very flexible and two runs in parallel forms a nice strong fly-lead. I was able to make a much better soldered connection after cleaning up the corrosion on the terminals. A new shorting link made from the same cable completed the repair. Easy peasy lemon squeezy.

I’m packing up ready for a business trip next week followed by 4 days SOTAing in OK and probably SP with WX looking nice. I looked at the coil and for no good reason found myself with the Ohm meter checking the continuity. Hey… this has just been fixed why is it open circuit? Well one of the wires from the 30m coil wasn’t actually connected having popped off when I was cleaning the corrosion. A quick zapping with the iron and we’re back in business.

I have no idea why I didn’t check it when I did the re-work yesterday but I’m glad I did today. Sure something could have been bodged but it’s so much easier to give the gear a check over when you have time rather than panicking when you are 1800km from your shack workbench! Suffice to say, lots of other stuff is being carefully checked as it gets transferred from the UK-SOTA bag into the EU-SOTA bag!

Fail to prepare… prepare to fail. As they say (much to Tom M1EYP’s annoyance.)


#2

The humble Ohm meter is easily overlooked in the context of RF, but it can be really useful for checking antennas, especially where joints are covered in insulation and cannot be inspected.
Not SOTA related, but this came home to me when I checked the dc resistance of an old mag mount, from the centre pin of the connector to the antenna element. It read about 10 Ohms! Investigation found corrosion inside the mount, which was easily sorted, once identified. I wouldn’t have hacked open the mount just to look…


#3

I use sections of this type of cable to improve the flexibility at the connection points of my antennas. This has resulted in far fewer failures than making the connections with standard pvc coated wire.

Periodic visual and electrical checks are an important part of the preparations for activating, especially when a lot of time and expense has been put into the outing. The 6P principle applies!


#4

The repaired loading coil worked FB today. Tomorrow’s target is 50pts. Typing that reminded me to put the LiPo on charge!


#5

Bah! The failure monkeys have been out in force today.

1st failure. Zip failed on my new Dxpedition SOTA rucksack. Chinese junk (albeit not cheap). A running repair was made but that cost me 25minutes.

2nd failure. 817 had a major fit when powered up on the first summit. Display was flashing on/off. Power cycling did nothing to fix it. I vaguely remember something about battery voltages. So I powered it on the internal battery and it was fine. Attached Lipo and still OK. Anyway I’m going through a cargo-cult mode by powering the 817 on internal batteries and then attaching the Lipo. Power is the reverse… detach Lipo then turn off.

3rd failure. I trod on the Mic cable connector and it’s no longer 100% as provided by Yaesu. If I jigger it then it works. I’ll look at swapping it and apply insulalting tape to see if that will effect a cure that lasts for the trip.

4th failure. I forgot my fleece or waterproof. i.e. I was attempting 5 summits all above 1000m in mid October with no warm layer. I did some sums. The WX forecast was to be sunny and similar in temp to yesterday. It got to 25C here at 450m ASL. Being 600m higher would drop the temp to maybe 20C. It should be OK was my thought but it was windy and that windy had a cold edge. Still it was hot enough that I drank 1.5L of water on a 12km walk.

Still all the issues did not stop me activating 5x 10pt summits. And now I am going to activate the hotel bar!


#6

Well done Sir, you overcome those issues extremely well! Enjoy the lovely Czech beer…


#7

My FT-817 does this occasionally - maybe once in every 25 activations. Perhaps I ought to have had it looked at under warranty, but the problem is so intermittent that it would almost certainly have come back “no fault found”.

I have read that it is a symptom of PLL lock failure. For me, it usually goes away if I leave it alone (switched off) for a few minutes. My technique is to go over to Caroline and cadge a contingency contact or two on 2m and/or warn her that I might need to borrow her radio later. When I go back and try again, it’s usually fine.

I’ll try your battery trick next time.

Martyn M1MAJ


#8

It scared me Martyn. I’d done two easy summits the day before whilst driving from Prague to Náchod but I gave up on more because I was exhausted as I’d had 2 early starts (0315 and 0445), 2 flights, 2 coach transfers plus 3 days of partying, sorry hard work with my colleagues so I was really tired. I was looking forward to 5 summits in the fabulous weather and firstly the zip broke on a new bag and then the 817 started acting up. I was 4km from the car with a bag that would spill its contents if I didn’t fix the zip and the radio was misbehaving. Looked like a disaster was looming. Then I trod on the mic connector and banjaxed it.

Getting the display to stop flashing relaxed me a little. Getting the 4th contact was uber-relaxing. I’ve done this nearly 600 times, so be anxious as to whether I’d qualify or not should be a thing of the past. The 817 has been OK since. But I’ll leave it on test for a few days as I’m off to Feurteventura for a week of sun, SOTA and family fun in 3 weeks.

I’ve just picked up a crimp tool and a bag of RJ-11 (or whatever size they are) connectors so I can repair both 817 microphone cables. I might be able to actually talk to someone on my next SOTApedition!


#9

Well I practiced putting a few RJ-45s onto a piece of scrap ethernet cable, trivial. I’d never done it before. Ethernet cables come from the big box in the server room but I suppose you can buy them! Then I spent 3.5 hours trying to fix my two FT817 microphone cables. I found a short length of shielded Cat5 cable and that works of course but I’m not sure if there would be RF pickup as I couldn’t check how the shield is connected with ripping it apart. Suffice to say, the genuine Yaesu cable has the mic signal wire shielded as well as a ground for switches and PTT. Anyway, the second repair took about 10mins having learned for 3+ hours on the 1st one. It doesn’t help that I no longer have the eagle eyes of my teenage years :frowning: