Monthly Archives: August 2016

Haltron CV8067

I just added a CV8067 to the site. This is one of a number of Haltron valves I have noticed recently on eBay where the valve just carries the CV number. All those I have noticed are in the CV8xxx range.

Now K1001 does permit this but specifically when it is “impractical, on account of physical limitations” – see here¬†(pdf) section 4.1.4. It is hard to see how a valve such as this example could not carry the full CV information. On on a subminiature valve, but not here.

The valve came in a Haltron box with no markings, and a label attached giving the CV and NSN numbers.

Looking at the valve the printing is slightly different too, as if the original Haltron marking is the original and the CV number added later. There is no obvious evidence of the civilian part number being removed, but of course it may just have been cleaned off sufficiently well as to leave no trace.


Another little sequence completed – I now have all four magnetrons from CV1475 to CV1478. These are four frequency variants and successors to CV69A-D.

I have CV69A and D too, so now need CV69B and CV69C to complete that set.

There are two other sets of four – CV1479-82 which I have already and are CV76A-D (I have CV76B and C, so need A and D, and CV1483 to 87 which are CV99A-D. I am missing CV1483, and CV99B and D.


Gnu radio

Not really valve related (ok, not in the least valve related!) but after a lot of messing about I finally got Gnu radio to work last night on Ubuntu 16.04. I say finally because it was the end of a lot of messing about off and on, and in no way the fault of Gnu radio.

First, some background. I’ve been using Ubuntu since version 7 I think. I settled on it because it was easy to install on the old and dodgy hardware I had at the time – other distro’s would not even install. My current PC had 12.02 LTS – I use the LTS versions as they have, well, Long Term Support. I had an older Gnu radio package set up and working but it later broke and I’d no idea why. Anyway, I had no time to fix thing back then.

I got back to it later but never fixed it, so I installed the then latest Ubuntu 14.04 LTS. No matter what I did I could not get the software to work. As it was nearly time for the 16.04 release I left it.

I installed 16.04 LTS a couple of days ago but again Gnu radio failed. The software would install via apt-get but gave errors when running. The script (below) failed to complete. Again, no time to fiddle.

Last night I wiped the PC and installed a clean Ubuntu 16.04 LTS and this fixed things. The excellent script (below) ran and set everything up. I had to fiddle with the USB settings and blacklist a kernel module but this is all documented. Finally, I got a basic FM radio working to prove the installation is ok.

So, although upgrading Ubuntu is generally OK for mundane stuff, it is clearly a tad off for actually getting the system up to grade. A clean install is a far better option, and indeed is recommended. Having more than one physical disk makes this a lot easier as one can copy anything needed to the other disk, or have home volumes on that other disk, and trash the o/s disk for each clean upgrade.

This script ( is really useful and does all thew work for you.

The morale – don’t be lazy! Now for the interesting stuff…


CV1931 update

For some time I had a CV1931 on the website, the example being a 6H6 metal double diode, though not 6H6 marked. Today I got a glass CV1931, also marked 6H6GT. I never checked before but the metal one is clearly incorrectly marked.

The CV Register has three CVs in a  series: CV1929 / 6H6G, CV1930 / 6H6 and CV1931 / 6H6GT. This makes sense.

For now I’ve left the page as-was but added the glass valve.