Ouch - That's Noisy!

Well,

You may remember the radio I acquired a while ago, back here:

http://g0mgx.blogspot.co.uk/2013/10/another-one-really.html

And the trials and tribulations I have had over a suitable PSU for the PA in the radio. Well, eventually I have received a unit I bought from China. It's stuck in a box and looks like this:

Now, currently this SMPS is generating some horrendous noise from about 4MHz to about 6.5MHz (and probably in other places as well!). The noise is only audible on any of my radios with an antenna connected; nothing with the antenna connector pulled out.

There is a very bad example of the noise on the 60MHz CW frequency 5.373MHz, however if I stick the antenna into the Spectrum Analyser, I don't see anything different with the SMPS on or off, the trace is the same:

Odd, egh?

** UPDATE **

I conclude that the SA is nowhere near as sensitive as a HF receiver - hence the trace above doesn't show the QRM.

Anyhow, following some exchanges on the RSGBTech Yahoo Group, I've had some great advice from some SMPS wizzos and we ended up removing the earth from the SMPS board itselt (don't try this at home) and connecting the -ve power rail to the metal case and hence the mains earth.

Result? Problem solved - the noise has been eliminated.

The RX On the 1000MP is excellent, I've rearranged the shack to accommodate the radio a little:

The photo above was taken with the panoramic feature of my Nikon Coolpix - good egh?

Really, Build Three?

Well

Been fiddling some more with the PSU I made for the FT1000MP I acquired back here:

http://g0mgx.blogspot.co.uk/2013/10/another-one-really.html

I've been using some halogen bulbs as test loads for the 13.8V PSU (they are 38W so at 13.8V that's a current pull of 38/13.8 or 2 3/4 Amps. As the FT1000 requires about 2 3/4 Amps for the 13.8V line that seemed just perfect to me!

I wasn't happy with the voltage drop I was seeing in the 723 based regulator under load, I also was far from impressed with the fact that I managed to destroy 2 of these 723 regulator IC's during my testing, I suspect some very suspect ebay sold components!

I've remade the regulator board using a L200C regulator I found in my component stock, it's quite a nifty device with similar current protection as the 723. Here's the new board:

Stuck in the same box I put the first one:

I had a very quick play in the RTTY Makrothen contest today, I only worked about 35 stations - mainly as a set up and config test for the JARTS test next weekend which I will be participating in. Here's the obligatory log as a map:

Young Florrie Cat hasn't been helping much:

Fun though, egh?