QSO with CT2JTZ

Visit to CT

Last thursday I received a phone call from EA1DK, Fernado told me he had been QSOing with CT2JTZ Thierry who is Telecomunication Engineer(like me) is keen on mirandese language(me in leonese, both are same languages with different local names)
It was a big coincidence because I had planned to travel to Braganza next day just few km away from Thierry, so I decided to find out info about him and visited him.
I arrived Thierry's town on Friday afternoon and I met him! He was surprised for the visit. We spent a nice Friday with him, he show us his town, the petroglyphs, even invite us for dinner at his home(tks to his mother)
Next day 22 I hope to visit him again.
Here is a photo from my visit:


Why I use the CT7 prefix?, read this

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:

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.

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.
73!
Here is a demo video:

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.

Receiving the Digital Radio Mondiale with Kenwood TS-450S and series

The TS-450S radio and related series(TS-850, TS-690) has a connector in rear panel labelled as DSP2. This connector was original used to supply the 4th IF to optional DSP-100. This signal has a frequency of 36.891 KHz, so with a simple converter it can be moved to 12KHz, then sampled with a computer's soundcard and processed with any SDR software.

I use this signal to receive the Digital Radio Mondiale with Dream Software.

I made a prototype converter, based on a double balanced mixer. Now I am working in a more sophisticated mixer with less intermodulation and higher SNR.

The prototype