Being thrown off the scent

Yesterday I decided it was time to cull the excess RG58 running out to the dipole. There were quite a few spare metres laying about. I took the soldering station out, put on new PL259s and shoved the joiner between them. 

Why join? Because the "long" cable would never make it to the shack, and to be honest, I wanted a point to tap outside that I could wire into when I experiment but am too lazy to drag all my gear out with it. 

Anyway.. I did this, came inside, fired up the radio.. and the tuner.. the tuner will show me the SWR if I don't tell it to tune, and I was told it lacks any kind of memory. 

So, I fired it all up, and came straight out with a reading of 9.99:1. Basically off the chart, and consistent across bands. Hmmm.

I went outside again, multimeter in hand, and checked continuity as well as I could. I even rejoined the plugs on the off chance that the adapter was dodgy. 

Back inside, no dice. It finally dawned on me.. there's a reset option on the tuner.

All of a sudden, 40m is back to about 3:1. So... don't entirely trust the SWR meter on the tuner unless it's reset first. Unlike the one on the IC706, it's at least readable. Obviously this is by no means a "great" SWR, but it is at least no indicating something more dramatic.  Obviously I'd like it resonant, but there is that matter of 6 odd metres of ladder line between the antenna and the balun. Solve one problem, create a new one I guess. It does cost me a chunk of power getting to the antenna though. When you're limited to 10w, loosing a couple of watts matters. I may need to do some more experimentation to confirm that I get SWR at the feed point from the antenna. Perhaps that might help me see the effectiveness of the balun. 

I guess the moral to this story is not to trust the readings of a device that intentionally changes anything. There's probably a lot to be said for having a dedicated SWR meter (and power meter for that matter) in the chain before the antenna.  Both are things that the ATU-100 tells me, but I'm not sure I really trust it "that much".

I put one of the spare studio monitors on the desk yesterday... after fixing the centre cone on the woofer that my son had so kindly pushed in at some point. I've taken it's shiny outer coating off it thanks to the tape - I had tried the old vacuum cleaner trick that has worked for me before, but alas, not on these speakers, but it seems to work. I have it a quick test run last night and it did make a difference over the built in speaker. A lot more clarity, and I can crank the volume up a lot louder. It also lets me filter the high frequencies out too, so that's a bonus. I just need to remember to turn it off. It pulls around 70 watts @ 240v, so it's by no means power efficient.

I ordered the XGGComms Digimode-4-Icom yesterday. This will allow me to run the IC706 with digital modes. Never something I'd really planned on but it seems useful. It should be handy when the next ISS SSTV events run too given I should be able to fully automate that. Being able to go both directions on VHF with SSTV is something I look forward to. The only issue I have is that this works off the 13pin DIN ACC port. I also need this port for PTT control to trigger the QRM Eliminator. I've found a Y adapter that is 13-13pin, but they're rare. I don't really fancy trying to make one myself. It'll likely cost me $30-40 just to get the plugs and a socket. It won't cost me much more to get one made by someone. 

This gizmo looks to be well featured. Supports digital modes, has a built in USB sound card and has CAT control. All useful given it'll be the second radio on the PC. A lot less expensive than a SignaLink.

At some point in the future, I'm expecting to have to go back to work despite all arguments against the need for such a thing, so it'll be useful to be able to remotely drive the shack to fill in those lunch breaks. From an IT perspective, that's no issue. As one might expect, an experienced system administrator has remote access via VPN to his own network. The challenges here are the things that need to be done manually:

- Tuning. The IC706 uses the ATU-100 and that requires manual intervention. It's not going to last an entire day on battery if I set before I leave, and I'm limited to a single band, within reasonable tuning distance of where I push the tune button. I can leave the power cable plugged in, but that does bring a little noise. If I was a really clever nerd, I'd wire a circuit into it that'd allow me to trigger it remotely. I'm not. Best I can do is leave the power on and tune it close.  The G90 however doesn't give me this grief.

- Charge. I run off battery. The 240v to that battery charger is controlled via a hard switch in the shack that drives the charger in the garage. If I remember to turn that off before I leave, then it's all good. Potentially I could use a wifi driven plug to turn it on & off as well, but it'd need to be a cloud connected gizmo that doesn't rely being on my local LAN. I could get around that by VPN on my phone, but that's a lot more effort. Options at least. Either way, it's gotta be off. It generates enough noise to completely wash out the HF. I could of course just buy a decent power supply that won't murder HF, but I'm not keen on re-buying things.

- QRM Eliminator. That'll just need to be in bypass while I'm not about. I can live with that. It's only intended as a signal improvement device, and it's likely to be difficult to use outside of phone (and some would say it's difficult even then).

I can't solve all the problems of the world, but at least I'll be able to play with digimodes while wasting my lunchbreak.