View Full Version : A home for the Sat-Schneider DRT1
FritzWue
16-07-2005, 19:37
The DRT1 mounted on the evaluation board is only 10 by 8 cm.
I found a case with 10 by 14 cm, so I could put the receiver, a voltage regulator plus fuse, the on/off switch, a -14dB attenuator, an agc potentiometer, and the s-meter into it.
I also used a small Yaesu FRT-7700 tuner as preselector at first, but found that most time there was no improvement. Perhaps the micro inductivities in there are not good for the signals. So now I only have this little box and outside an untuned T-antenna 22m high with 2x 40m toploading wire.
The box works perfectly with the DREAM receiver control, and a good alternative is the G8JCF software which has a lot more features when listening to broadcast or amateur radio.
http://www.g8jcf.dyndns.org/
In all it is great fun, s-meter illumination is with blue LEDs. :cool:
Hi Fritz
RNZI have loaned me a DRT1 receiver to try for a couple of weeks. It is not as impressive looking as yours - just a plain rectangular box!
Originally posted by FritzWue
The box works perfectly with the DREAM receiver control, and a good alternative is the G8JCF software which has a lot more features when listening to broadcast or amateur radio.
http://www.g8jcf.dyndns.org/
In all it is great fun, s-meter illumination is with blue LEDs. :cool:
Have you used this software for DRM reception? If you have, how do you decode the audio?
73 Chris
FritzWue
29-09-2005, 07:26
Originally posted by Owdjim
Have you used this software for DRM reception? If you have, how do you decode the audio?
Hi Chris,
hope you have fun with the DRT1.
Peter Carnegie's G8JCFSDR does not decode DRM, it is just for AM, SSB, CW, FM.
There is a DRM button, that will switch off the G8JCF SDR and start DREAM on the just tuned in frequency.
This is correctly working with the latest version of the software. Uninstall any version from "software" in the windows control panel, delete the G8JCF folder under programs, then install Build 89 alpha release and then replace the g8jcfsdr.exe with the renamed build 113.
This version also has an audio recorder, very nice feature.
Before you start open the "Full" display and go through "Config" at the bottom right.
http://www.g8jcf.dyndns.org/g8jcfsdr_drt1/g8jcfsdr_download.htm
Peter is very communicative and waiting for bug reports.
mailto:g8jcf@dsl.pipex.com
Regards
Fritz
Ah! That works *MUCH* better :-)
Many thanks!
Cheers, Chris
Hi
Here's a quick photo of the DRT1 I've had on loan from Radio NZ International. Not as nice an installation as Fritz's :-)
I've had to give the DRT1 back for now because there other unit has developed a fault :-(
Cheers, Chris
FritzWue
11-10-2005, 07:34
Internally my box does not look very nice any more, much more in it, but it works better now.
I never needed/ used the AGC threshold potentiometer, so it was replaced with a rotary switch to select one of four antenna filters.
direct
300kHz lowpass (strong locals on 549kHz and 720kHz)
1000kHz highpass (strong locals on 549kHz and 720kHz)
1600kHz highpass
9000kHz highpass
direct
On the rear a switchable 12V supply via coax for my car antenna preamplifier was added.
Hello Fritz,
I have followed your posts on this thread with great interest.
Sat. Service have sent me back a quote for the the DRT1, so I should be grateful for any advice for a beginner before sending for it... like do I need to include a preset for the AGC to replace the front panel control you had originally?
FritzWue
14-10-2005, 16:02
Originally posted by johnn
do I need to include a preset for the AGC to replace the front panel control you had originally?
Hello John,
you don't need to do anything, if you order the DRT1 on the evaluation board like I did.
On there is an agc amp that works very well. The agc voltage is fed to the DRT1 via a jumper. If you remove this you can replace it with a manual control,
or with an additional diode you may use the agc amp plus a manual agc threshold control like I had, but I never needed and never used it.
You find some details here:
http://www.elexs.de/drm8.htm
http://www.elexs.de/drm9.htm
Here you can see the red jumper connecting the agc amp with the DRT1:
http://www.elexs.de/drm10.htm
If you order the DRT1 without evaluation board you either have to feed it with a manually set agc voltage to prevent overload or you have to build an agc amp like shown above.
The DRT1 evaluation board's agc also works very well with Peter Carnegie's G8JCFSDR which also has its own software agc:
http://www.g8jcf.dyndns.org/
Hello,
I only can confirm Fritz`s experience that the AGC of the
DRT1 on the evaluation board works perfect. This is the first
receiver for DRM which doesn`t need a manual gain control.
Bernd, DF9RB
Hello,
an other home for the DRT1...
Plan A was to integrate an USB to RS232 converter and to supply the DRT1 via USB as the internal supply is 5 V. But the converter I bought could not control the DRT1 because of timing problems. So I realized Plan B.
The DRT1 now can be supplied from USB or 12 V DC. I found no degradation of the receiver performance supplying it from USB. I added a reset button as the control doesn't operate correctly when restarting Windows with the DRT connected. Further outputs are two 12 kHz outputs (the 2nd is 20 dB attenuated for my laptop which has only a microphone input) and a S-meter output.
Bernd, DF9RB
FritzWue
15-10-2005, 18:37
Originally posted by df9rb
I added a reset button as the control doesn't operate correctly when restarting Windows with the DRT connected. Further outputs are two 12 kHz outputs (the 2nd is 20 dB attenuated for my laptop which has only a microphone input) and a S-meter output.
Bernd, DF9RB
Hello Bernd,
nice looking box with very compact size, congrats!
I use my ON/OFF switch to reset the DRT1.
...and here have the same audio input level problem with my DELL Latitude.
I made a special audiocable with two resistors as voltage divider soldering one in series in the DRT1 output plug and one parallel in the DELL input plug.
The s-meter is very helpful, luckily I integrated it from the beginning.
Originally posted by FritzWue
I never needed/ used the AGC threshold potentiometer, so it was replaced with a rotary switch to select one of four antenna filters.
Thankyou for your posts so far. I will contact again about antenna filters later. My requirements may be different in UK.
On MW, 1296 is not intended for us, but it does sound good the snatches I get late at night!
Hello,
today I "calibrated" the S-meter connected to my DRT1. I used a simple frequency generator, measured at 200 kHz, 1 MHz, 10 MHz and used an oscilloscope to control the input level at the antenna jack. The AGC-voltage of the DRT1 is quite independent from the frequency applied and has a wide dynamic range. I can read levels between less than 5 µV up to 100 mV RMS.
The instrument itself is at least 30 years old but easy to read even from greater distances.
In the attachment you can see the signal strength of DW on 12080 with approx. 1 mV at the antenna jack
Bernd, DF9RB
mitajohn
19-03-2006, 10:56
Hi all,
I'm in the way of building a DRT1+Evaluation board, receiver. The metal box I use is a low profile one and I want also to install a nice edgewise s-meter (100uA). Has anyone any idea for a source to obtain this meter? I searched the net but I haven't found a good source. Thanks.
John.
FritzWue
19-03-2006, 19:35
Hi John,
do you mean something like these?
http://business.lieske-elektronik.de/artikel_713493.htm
http://www.shop3000.de/index.php/cPath/17_296_297?osCsid=7a6a2ed068c057b2b73daa20ee7a8d35
http://www.hinkel-elektronik.de/shop/4440.html
Looking at the prices they must have golden wires inside. :rolleyes:
Checked my box, but nothing like that in there, sorry.
You'll have to kill an old DRAKE! :cool:
http://www.dproducts.be/DRAKE_MUSEUM/images/TR4.jpg
mitajohn
19-03-2006, 20:02
Yes, something like this.
Thank you for the info.
John.
FritzWue
19-03-2006, 21:55
By the way:
Congrats to your new toy.
Good decision!
a few minutes ago...
Best performance I've ever seen so far in terms of SNR vs. RF-Level.
FritzWue
28-12-2006, 21:02
For a test I installed one of those USB-RS232 adapters.
The DRT1 works with this, although tuning is a lot slower.
Still OK for DRM, but not really fast enough for tuning AM/SSB.
mitajohn
29-12-2006, 14:47
Hi all,
Bernd has reported in post #10, in this thread, that he has tested DRT-1 controlled and powered by a USB connection with success.
Last year I had tested the DRT-1 and Elektor, using both of the USB to Serial adapters, as seen in the attached pic.
-Using DRT-1 with the USB adaptor, except of the very slow response of Dream or Disco, especially when browsing frequencies, the RX worked OK.
-Using Elektor with the USB adapter, except of the above behaviour of slow response the Elektor appeared a problem with Dicso, ie: whenever the Disco window was updated the IF output of the RX was cut out for a second or two and then came back again.
Generaly I didnt like the control of both receivers with the adapters. I am planning now to use a PCI to serial card (see the pic). Have anybody any experience ?
FritzWue
29-12-2006, 15:10
Generaly I didnt like the control of both receivers with the adapters. I am planning now to use a PCI to serial card (see the pic). Have anybody any experience ?
Hi John,
my DRT-1 is also responding too slow for me via usb.
Maybe I need a new notebook next year and then it will probably be difficult still to get one with serial connection.
I already have bought a pci card with two serial interfaces,
but as all my motherboards still have RS232 I do not yet need it,
so you first. :D
Hi all,
I bought a quite cheap USB to RS232 converter a year ago or so (see attachment).
It didn t work with the original firmware and the DRT1. I found out that a FTDI chip is used in this converter. After some searching in internet I found an other firmware named FTDI2154_64.zip. (I have it on my HD if someone needs it) With this new firmware the converter works perfect with the DRT1.
Bernd, DF9RB
Correction:
Not the firmware! I meant the windows drivers
An other correction.....
The correct driver seems to be R2176.zip. This driver has the same version and date as this one installed on my computer. The above mentioned is for 64bit as John mentioned. Sorry for the confusion - but I tried a lot until it worked and did not delete the unsuccessful driver from my HD.....
mitajohn
30-12-2006, 18:24
Hi Bernd and all,
Yes, this is the blue one in my 1st pic, the black one is a HP with the same chip. I had found another driver but it didn't work good, too slow. Lets test yours, please send it to my email. Thanks.
Correction:
I think, is this driver for AMD64 and XP64 or not? If yes it would not work for me...
Here we are now...a new release "CDM 2.00.00.zip" (for W2K) from http://www.ftdichip.com/FTDrivers.htm
FritzWue
30-12-2006, 21:56
I just checked my working low cost branded USB1.1 - RS232 converter.
Inside is a Prolific PL-2303 with driver ser2pl.sys.
http://www.prolific.com.tw/eng/Download-2.asp?ID=17
Hello,
I have bought the Sat-Schneider DRT1 on the evualation Board, but I don't
receive nearly anything with this receiver; I tried a telescope Antenna and a
long wire (ca 12m) and a homebrew little amplifier.
I used the G8JFCSDR and the Dream Software, but I got only very much noise
and only one or two time a little signal from DW on 6075KHz in AM. What have
I to do to get any reception? Are there any tricks to handle the soundcard?
I would be very happy if anyone has any suggestions
In hope of an answer
conti32 (DB4QF)
mitajohn
22-01-2007, 18:21
Hi Conti32,
Please state your DRT1 configuration.
For testing use ONLY Dream, check the soundcard and remote settings and feed the line in (check line in recording) of the soundcard with the DRT1 IF signal, check the level at about -10dB (no noise reduction systems or gain boost) and when everything is connected and Dream runs, switch off and on DRT1. Just some thoughts, DRT1 is a very good receiver for DRM.
Hi conti32,
can you please post a screen shot from the input spectrum in Dream?
Are you using a laptop? If so let it run on batteries, disconnect the power supply as this could be the reason for the high noise level.
Simone
Hi all,
thanks for the replies, I will try the advices and will post a picture from the screen, but I can do it in few days cause I am very busy at time
conti32
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