Techie bits 1

Amateur radio, a hobby for experimentation, investigation and learning.

Me?  I'm poor so I build or buy things that have function, they're usually not that pretty but they get the job done.

I've got a nice, simple, HF radio, the Icom 718, it's not got a lot of bells and whistles and a lot of 'serious' operators will (and have) sneer at it, preferring something with more buttons, knobs and switches than a NASA control room and enough processing power to find the meaning of life (42) but my little Icom is capable of 100 Watts across all the HF bands, works as a general coverage receiver  and was cheap enough for me to buy.

I like it.

I wanted to try digital modes, WSPR, FT8 etc. and to do that I need a computer interface.

I went looking to buy one.

Ouch.

They're ridiculously expensive for what I thought must only be a few bubble gum components.

I started researching to see why, what the secret sauce was that meant they were uncomfortable for my wallet.

Here's the secret, there isn't any secret sauce.

You're paying, at least for a clone CAT interface, for smoke and mirrors.

OK, so there's lot of information on the web about these gadgets and no, you don't have to spend a lot on them if you build one but, most of the interfaces on the web have a few problems or are just fiddly but, firstly and possibly the most important, they're usually designed for true RS-232 signalling levels, +12V and -12V.

Now I don't know about you but I don't have a laptop with a serial port and even when I did, it didn't have proper RS-232 levels so at best the simple interfaces were going to be flakey, to some of the designer's credit, they acknowledge this..

I also didn't fancy building something that could, potentially (yes, pun) fry the CI-V port on my nifty little IC-718 so I checked again, found a CI-V to USB interface for under a tenner and flexed my plastic.

It arrived in the post and I tried it out, worked a treat, I can tune the radio, choose bands, set mode etc. with Ham Radio Deluxe (again, ouch expensive and wow, let's not get into the discussions of blacklisting etc. I won't be buying a copy just because of that)

But, even though £9.95 is reasonable, I wanted to know what's inside it so the case got opened.

Well, that's a bit of a disappointment, it's a simple CH340G USB to Serial converter. There's no magic, that's all it is apart from a length of screened cable terminated in a 3.5mm jack plug.

Ummm...

I've got a few of those lying about, they're dirt cheap, less than a quid each on eBay (I like the ones with the gold plated border, I think it's going to be handy for shielding).

Of course I had to try one with HRD so I hooked it up to the radio.

Yes, works perfectly.

So, tip number one, don't bother with a CI-V interface, just grab yourself a cheap CH340G USB-Serial adapter from eBay, I got mine from this listing

But, not satisfied, I wanted it opto isolated and of course, I need audio.

More in the next post.