Monday, August 24, 2015

RS-232 disappearing from PC's and so is PCI.... so now what to do when you run Linux as a HAM?

Hello all,

Well, it's no surprise that I am a big fan of Linux. On my blog I usually post about Linux stuff often enough.

Recently I bought a new PC. I used an "old" AMD 64 X2 4000+ with 8GB DDR2 800MHz memory, and I thought I would spoil myself with a new one.
As it was going to run Linux , it did not need be top of the line, so I bought myself an Intel Core i7 with 16GB 1600Mhz memory.
And when it arrived I started to add my SSD to it, and installed it next to my desk.....

Now, as you might know, I use a Kenwood TS-480satt, still love it, and that uses a RS-232 bus to communicate to my PC (and so do most transceivers, as USB has just come to the very latest models of all normal brands). And for as far as i know, most rotators use rs232 as well. My old PC had 3 of those RS-232 ports as I added an PCI card with 2 extra ports.

Now... my new PC had.... NONE!!!...... So I thought that I would just add the PCI card to the new PC. CRAP!!.... it has no PCI buses either! So this card became useless.....

So I started to look on the one site that solves 99% of my problems...
And I found myself a new PCI-e card.....

Now you have these in 2 and 4 ports , or 1 parallel and 2 serial ports......
And they claim that these work under Linux..... NO THEY WILL NOT... (at least not out of the box, and not without tinkering a lot on your system) They are not worth to do so anyway....

These cards use a chip-set called CH382L and those might work fine with a simple driver for windows(not tested), but for Linux they are a major pain up the a$$ as this chip-set has not found its way to the Linux kernel (yet).

I tried 2 nights in a row to fix this... no luck what so ever.... google did not help a lot either, it just came up with a lot of results of either not working solutions, or people like me searching for a solution....

So, now how to solve this..... EASY ... buy the proper chip-set....
I ordered a very nice version , with a breakout cable for 4, yes 4 serial ports. (and you have them for 8 ports as well)

The chip-set it uses is: MCS9904
And I bought it with this eBay seller... eBay seller "only" 24 euro's
There is also a MOSCHIP 9901 chip-set, for a 2 port version, which I GUESS will work too.
I did not test one (yet). Example: eBay seller

Now this MSC9904 chip-set does work out of the box when using Linux Mint 17.2 (so my best guess would be that Ubuntu and Debian will work as well as they are builds from the same Linux tree)

When using those cheap a$$ USB-RS232 cables, it usually means that as soon as you start to make a QSO , the cable malfunctions. this PCI-e card does not have any problem with that.

An other HAM, who tested one of my cables, said that this usually has to do with the harmonics of the used frequency being too close to the internal oscillator or the max232 ic used in the converter.
I personally think this could be solved with proper shielding and such, as my way too expensive cable has no problem with this for as far as i know.

So as a conclusion, as long as you buy the MSC9904 chip-set, you're good to go!
I noticed that if it has this chip-set, they will write it on the eBay page. I guess the sellers found out that Linux users are looking for this ;)
Yes, it is not as cheap as the others, but this at least works.....

Hopefully this will help you out when you buy a new PC without PCI and RS232 (which is basically any new PC you can buy these days.)
If any one found another chip-set that works, please do tell us in the comments!!



  1. Alex, I too lament the lack of -232 support on recent computers. I've been able to use USB-to-RS232 "dongles" with pretty good success to control my TNC's (Kantronics & Argent Data). The most dependable one I've tried is the Belkin model FSU109. In the Linux /dev directory, it shows up as the ttyUSB0 device. And a quick command of lsusb can show you the connected interfaces on USB. I've not tried any CAT control with this Belkin dongle... so I have nothing to contribute in that area. A fellow ham has told me to get into the CAT world with my radio, so maybe I should give it a try. If I heed his advice, I'll let you know how this Belkin does. -73's, Mark Rice, KK5MR

    1. Hi Mark, your using it the exact same way i do... and there for run into the same things as i do.
      Often the cheap usb converters/cables will fail as soon as you transmit.
      The more expensive ones (like belkin) usually will do fine....

      good luck, and i hope to hear about your results....


  2. I have had similar problems, I still like RS232, it works well once you configure it correctly.

    Similar card with MCS9904 chip on Gearbest for $16:

    I have used them a number of times now I find they are quick at despatching goods..

    73 Steve


    1. Hi Steve,

      Damn thats even less then i paid :)
      I will keep that in mind if i need another card.
      I have used my card for a while now, and i have had no problems what so ever... so i am happy!

      Thanks for your reply!


  3. Been there got the T shirt, you can always find it cheaper after you have bought the item..

    I have had a few things from Gearbest seems ok, although a Chinese Website, stuff to the UK comes via Rotterdam, so you dont get stung for customs duty..

    I will put you in my Blog roll when I get the time..

    73 Steve