Tuesday, 29 July 2008

DL8BEG reproduces EA1GHE`s downconverter

I have received an e-mail from Werner(DL8BEG) who successfully reproduced the downconverter that I designed to receive DRM with the kenwood TS-450S radio.
Werner found a mistake I made in the drawings(now corrected):

Thanks to Werner for his correction.
This is a photo from his circuit:

Sunday, 22 June 2008

Recycled ferrite sleeves from the rubbish

There is one cheap way to get ferrite sleeves for EMI troubles. Get the sleeves from old computer screen cables. Just use a knife and extract out the ferrites.

Monday, 26 May 2008

Receiving DRM with Kenwood TS-450S (II)

For those who are interested in receiving the DRM using the TS450 radio by Kenwood, here is a pdf file with the details and circuit. Remember it's also valid for TS690, TS850 and TS950 radios wich has 4th IF output at 36.891KHz for use with optional DSP-100.
I am waiting for any feedback.
Here is a demo video:

Saturday, 5 January 2008

RF interference from Sony TV set

I had a Sony TV set model KV-14M1E. Every time it was turned on(even in stand-by mode) I received an annoying QRM from it in my amateur radio. Since I know that the interference came by radiation one day I decided to open the TV and explored the circuit with a small loop probe. You can see how I did it in the next video:

I discovered two loops radiating RF:

Like a solution I was thinking about decoupling these loops with the right capacitor but I had got no time to do the modification, the TV set was taken away from my QTH.
Now my spectrum is clear, more or less, of human-made QRM.