Not strictly ham radio related, other than the fact I’ve got a Morse code tape for it, but a vaguely technical project and interesting. One of the club members has been getting rid of old gear in preparation to move house and no one else was interested so I was lucky enough to become the owner of this beauty!
As it’s not been used in years I’ll need to recap it, I’ve ordered a recapping kit but I probably won’t get round to doing it for a while.
I’m now thankfully back on the air, I attached the wire to the new potted N-type balun using ring crimp connectors, but this time rather than Silkaflex or solder I’ve used some Araldite in the connectors and self amalgamating tape around them to try to avoid water and air getting to the connection. I’m not sure that this will work any better but worth a try, I may need to source some new wire with less of a tendency to corrode for next time.
I also took the opportunity to slacken the wire to get the balun as high as possible before clipping it back on to the gutter. I fold the ends so can afford to lose a little bit when I add new connectors, but it does get more difficult each time…
I’ve checked the SWR readout and am happy with what I see.
While I’m off the air I thought I’d start preparing the PCB for the next portion of the sudden transceiver which I’m (very slowly) building, the power amplifier. I’ve not really been working on this project just due to lack of spare time at the moment as I’m focusing on CW operation while the bands are good, I know that during the winter I’ll struggle with my evenings on 20 and 40 meters, although I might try to put together an 80m compromise antenna in the loft or across the garden for the winter.
So I’ve had a little investigation into my antenna issues, I brought the antenna down on the winch took a look. It looks like the tape over the crimp connectors has reacted with the Sikaflex in some way so water may well have got in there. I stripped off the Sikaflex (which I wont use again because removing it is a sticky nightmare) and put Araldite over the cracks. After winching the antenna back up I checked the SWR trace again and it had got even worse, which was similar to my experience last year.
Looking at the balun there are a fair few cracks which I’ve temporarily protected with Araldite, it’s also not potted and uses a SO-239 so I’ve chosen to replace it with a potted balun which uses an N-type connector which are what I use elsewhere in my shack and what I’ve got on the end of my coax, this allows me to remove the N-type to PL-259 adapter.
Unfortunately for the third year running at almost exactly the same time of year my antenna has stopped working. I noticed that the ATU was struggling to get the SWR down to where I would expect so I connected up my NanoVNA and noticed a bizarre trace.
Having had a quick look at the antenna it seems to be the same issue, corrosion of the wire that makes the legs of the antenna, I’d used significant quantities of Silkaflex sealant to try to avoid the water getting in so that’s a bit disappointing! After having a think about the issues and a chat with some of the club members it was also suggested that the issue could be water in the balun.
Given that the balun is a bit long in the tooth and already had a small crack protected by gaffa tape I may replace it.
Until I can sort things out I’m now off the air which is very frustrating. Like last year if feels as if it has happened just as I’m getting the hang of CW, last year it was around my first couple of QSOs, this year it’s as I’ve started getting in the swing of a few QSOs each week.
While I’m off the air I’m using my spare time to read Bill Meara’s book SolderSmoke ‘Global Adventures in Wireless Electronics’ it’s a really good read and I might post a bit of a review on it at a later date.
