Another week in radio

 

Again, I suck at blogs but it’s been a big week in my world of HAM.

I pulled the trigger on the Xiegu G90 and a trapped dipole kit. It’s all on the way, along with earth stakes, earthing cable, an SWR meter for VHF/UHF and various other sundry bits and pieces that I really can’t afford.

I received the Retevis RT95 dual band radio I ordered a while ago. One of the two hams who I’ve been chatting to via email did point out that it’s missing some of the amateur band in UHF. He’s right, it is, but the radio can at least hit all of the repeaters that I want it to (edit: the mode can be changed to open it up).

Retevis RT95 - Any Anytone clone.

 

It’s not a bad radio – a little odd to setup, but once I programmed it using CHIRP with a stack of repeaters, I was able to kick it over to name mode, and have it scan. Pointing at a repeater about 100km away I’ve got a readability of 4, Strength 7, using the discone with the roof mostly in between. Handy as it’s also an IRLP node. Interestingly, my SDR doesn’t seem to really notice much going on with this repeater.

The only thing that isn’t great from a foundation perspective is that it goes from 5w to 15w, and a foundation is limited to 10w. If nothing else that’ll give me motivation to improve everything else before I just blame lack of power.

On the advice of a more experienced ham, I’m going to replace the RG58 transmission line to the discone with RG213. There’s 3m of it coming from the discone, that connects to a 15m run. The 3m will remain as most of it is up the pole. The rest of the feed can get replaced up to the wall plate, and I’ll keep the RG58 for the patch leads inside given they’re a little more friendly.

There was a Remembrance Day contest this past weekend that gave me an opportunity to see if I could pickup some of the HF traffic. On the Saturday evening, everything was focused around 80m, but I really couldn’t hear anything.

On Sunday morning, not really seeing/hearing anything on 40m, it finally dawned on me that I needed to change the sampling mode on the RTL-SDR to the Q branch for HF. Once I did that, I was able to make out a lot of garbled noises. About an hour after the contest was over, I realised that I really needed to zoom into the frequency display in SDR# a lot further than I would with V/UHF frequencies. A little difficult with no experience trying to nail an SSB signal without being able to fine tune it.

I did find what sounded like a Tabcorp betting feed using SSB – which was a great thing to test with; unlike the contest which had short bursts of traffic all over the place, this was constant, so I was able to fine tune it, and move around either side to get an idea of what that would sound like. Note to self: narrow bands.

I later found some other signals around 40m that I could kind of hear, but they really didn’t last long enough for me to dial them in well enough to fully make them out. With some luck, once I get the G90 installed and an antenna running for it, HF might be a little more accessible.

In other useless news – I discovered harmonics on Saturday. I was poking around 23 MHz, and come across an FM signal booming in which confused the hell out of me until I realised it was a harmonic. Multiplied it by 4, and found it the actual FM radio frequency.