Receiver Measurement Data

[DRM-OM]

but in German only
AOR 7030 and NRD 525G (http://privat.albicker.org/kurzwelle-drm/umbau.html)

BER vs. RF-Level
SNR vs. RF-Level
AM S/N and THD vs. RF-Level

Hopefully more receivers to come.

[df9rb]

Very interesting measurements. My TS850 has a similar behavior as the NRD525. I am waiting for the DRT1-tests.....

Bernd, DF9RB

[DRM-OM]

Full report (http://privat.albicker.org/kurzwelle-drm/umbau-frg7700.html)
Measurement graph (http://privat.albicker.org/kurzwelle-drm/bilder/frg_snrkurve.png)
Comments welcome!

[DRM-OM]

Very interesting measurements. (...) I am waiting for the DRT1-tests.....

Bernd, DF9RB

Hi Bernd (and, of course, all the others)
here they are:
DRT-1 Report (http://privat.albicker.org/kurzwelle-drm/umbau-drt1.html)

[FritzWue]

:cool: :) :D
Thank you, now I'll have to modify my DRAKE R7 to top that result.

[df9rb]

Thank you Bernhard for doing all these measurements.
Last year I "measured" my DRT1 under home-conditions. I reached 47 dBs with the mixer as the limiting element I think (posted in MAX SNR Thread):
Hi,

I tested the DRT1 from Sat-Schneider with a signal from an upconverter and the DRM-CD from hsseppo.
The DRT1 delivers an amazing SNR of 47 dB!
(the varying of the SNR are caused by some alignment trials)

Bernd, DF9RB
Attached Images drt1_47db_snr.png (35.4 KB, 66 views)
drt1_47db_snr.png (35.4 KB, 59 views)

Two additons from my experiences concerning the analogue behavior of the DRT1:
- The sensitivity is not as good as the TS850. The ususal very weak signals from South America are better decoded with the TS850.
- On 26 MHz I can see some phantom signals in Input PSD using the Ham Yagi. These signals are not present using a "normal" SWL antenna or using a pre selector or the TS850.

But considered overall the DRT1 is an excellent receiver concerning thr price and size.

Bernd, DF9RB

[df9rb]

Hi all!

On medium wave my DRT1 synchronizes on a DC frequency very close to 12000 Hz, on higher frequencies the DC frequency is up to 12035 Hz on 21 MHz (execpt CVC from Chile!). Assuming that all (most) of the stations are transmitting on very accurate frequencies I presumed that the main oszillator of my DRT1 must have a frequency offset. Today I readjusted the main oscillator until the DC frequency didn t show more than +- 1 Hz difference from MW to 22 MHz. Now I have the following advantages:
I can use Dream with a very narrow start up parameter (-S) which results in very fast synchronisation after setting the frequency to a new DRM frequency (4 seconds instead of 8) and mostly seamless frequency changes between synchronized DRM station even over many MHz.

Bernd, DF9RB

[FritzWue]

Hi Bernd,

but don't set it too narrow or you will not be able to receive anything on 17660 kHz. :D
I am using dream.exe -E 11998 -S 1000 as a compromise.

EDIT: My DRT-1 was within 5Hz at the beginning, now after a year in the car it was at about minus 25Hz on the higher frequencies.
I just retuned it, but beware, the txco trimmer is very small and sensitive.
I'm now at about -2Hz, but the frequency goes up a little when it gets warmer, so I let it where it is now.