Hi to the Forum!

So after a couple of weeks using my new ColibriDDC I am very happy, except for a discovery I made yesterday!

I finally got my active antenna from LZ1AQ out behind my house about 25 meters away. One of my main interests is receiving VLF, LF & MF.

So on first start up on the active antenna, reception was great on all the HF Bands, until I started turning to VLF, LF & MF! Basically the bands were a wash with really bad noise.
First I guessed there was a problem with the grounding on the active antenna. However, after trying with two other SDR's I have (both USB powered) I could not replicate the problem.
This lead me to check cables to the ColibriDDC (enough ferrite beads, bad cables, computers etc)! After several hours I was getting to my wits end with thoughts of a problem with the ColibriDDC! It was at this point the only item not checked was the supplied PSU. So after double checking the required power etc, I decided to connect a radio grade non-switch power supply to the receiver I had bought some years back for another receiver.

Bingo! The noise was gone. I could now hear all on the VLF, LF & MF bands!

I was relieved to have solved the problem but at the same time sad that a poor PSU was supplied with the receiver (or could it be faulty in some way?).

I just thought it might be worth bringing this to the Teams attention! However please don't get me wrong I do love this receiver.

Most Kindest Regards,
Andrew Hall,
Lossatal, Germany.

Hallo regarding noise level, my ColidriDDC shows above S9 of noise level in all bands with a 50 ohm load connected at the antenna.
is it normal?
Thanks
Marcello

High reading of the S meter has been a problem for the ColibriDDC for several years. It is not of high priority for the Expert team.
I do not know if this problem is just on the ColibriDDC or if other SDR products are affected.

Ed Rios
KP4AKB/W8

Marcello, how long feeder/coax do you have to the 50ohm load?

I have no cable. it is a microwave dummy load on SMA connector of the antenna.
Power supply is not an issue.
Noise and S meter are at same level also with battery or high quality HP power supply.

I have seen a: 'fixed' note on the chat concerning the eesdr3 but for me no change also with ESDR3

Marcello

The problem for me started with a firmware change.

Its not a ESDR3 or ESDR2. The problem is with the current firmware

Dear Ed, thanks for supporting me.
Did you find a solution or simply you drop the problem?
Did you determine that the problem is reduced to a meter/indication issue or is it also connected with a high noise figure of the receiver.
I will do some test with a calibrated frequency source to see how it looks.

For sure in a comparison with the Sun SDR2 pro specially in VHF the performance are very very different. Colibri is of no use no matter which filter you put in front.

Thanks again for sharing

Regards

Marcello