Sorry, no. I have a feeling if I made the file available, there would be all kinds of them for sale in Eastern Europe and Asia
Pete
Sorry, no. I have a feeling if I made the file available, there would be all kinds of them for sale in Eastern Europe and Asia
Pete
Hi
I regret to hear that, since I live in that particular part of Europe. And I think it is a stereotype, just like the one about Texans having oil well on the backyard.
Take a look here: N0SS' Ham Radio Site - Elecraft Kit PCB Scans
Elecraft's K1 and K2 PCBs are available and I haven't seen any Chinese/European clones.
But this great project is yours and I know that it is your decision.
Will buy your PCB anyway, thanks for help,
m.
Oh, but we DO all have oil in our back yards
Sorry, but I speak from experience. I used to post Gerber files for people to use (for noncommercial purposes) - and for some projects I still do. But I have found at least 2 cases where people were manufacturing and selling my designs, without permission from me. It DOES happen.
Even that would not bother me so much if they just would have asked for my permission. I probably would have told them to go ahead...
If you really want the files, for your own use, and promise not to give them out or sell them, send me an email.
Pete
Guys,
I am thinking about building Pete's interface, just some questions regarding the BOM:
- Are the parts sourceable in Europe?
- Is it possible to get an enclosure matching the frond/back plates in Europe?
I saw somebody made a new pcb as the original pcb/bom was not practical in europe (BOM and enclosure), what are your experiences?
Thanks!
Edit: If somebody is selling his, let me know per PM.
I am thinking about building Pete's interface, just some questions regarding the BOM:
- Are the parts sourceable in Europe?
- Is it possible to get an enclosure matching the frond/back plates in Europe?
I saw somebody made a new pcb as the original pcb/bom was not practical in europe (BOM and enclosure), what are your experiences?
Thanks!
Edit: If somebody is selling his, let me know per PM.
Last edited:
What do you mean? I only found Pete is selling 'kits' of pcb and frond/back plates.
Is he selling full kits including parts and enclosure?
Pete was doing a kit, a friend built one, best ask him when he's doing the next lot if there's none on his e-bay site.
Andrew
A couple of things...
I've seen people posting about using a 12mH choke in the Vcc supply to the NDTD converter.... I've not read the whole 67 pages and 670+ comments, but this should be 12uH (micro-Henrys) NOT milli-Henrys according to MuRata's data sheet at http://www.murata-ps.com/data/power/ncl/kdc_ndtd.pdf.
Secondly, is there a consolidated list of recommended mods anywhere as I've not had time to trawl through this thread in its entirety (see above )
Thanks
I've seen people posting about using a 12mH choke in the Vcc supply to the NDTD converter.... I've not read the whole 67 pages and 670+ comments, but this should be 12uH (micro-Henrys) NOT milli-Henrys according to MuRata's data sheet at http://www.murata-ps.com/data/power/ncl/kdc_ndtd.pdf.
Secondly, is there a consolidated list of recommended mods anywhere as I've not had time to trawl through this thread in its entirety (see above
)Thanks
Here is a very good DiyAudio post to following: QuantAsylum QA400
I built Pete's Interface and I have used it with the QA400. I am still trying to understand all the gains and losses (that must be taken into account) between the DUT and the QA400 which are necessary for accurate final measurements observed on the QA400.
Here is a screen shot of the QA400 results from a Carver TFM-15 amplifier using Pete's interface. If you correctly map out all of the gains and then enter them into the QA400's software you get meaningful results.
Note: I am using an external generator instead of the QA400's internal generator.
The setup is HP339 Oscillator > DUT > Pete's Interface > QA400 > Laptop
Notice the figures report exactly 100 watts (verified with an external AC meter as measured on my dummy load). The reported distortion is also very close to my HP339 analyzer results. I was also able to determine exactly when clipping occurs by monitoring the spectrum for increasing harmonics. Clipping shows up on the spectrum well before you can observe clipping on the oscilloscope. Not perfect but also not bad for a inexpensive PC analyzer. A good tool for analysis paired with Pete's interface.
An externally hosted image should be here but it was not working when we last tested it.
If you are having hum problems with the sound card interface and you are not deliberately using the input as a differential amplifier try shorting out C2. The acquisition below was done at 100mVrms from an Amber 3501A with output in ground mode, and the input floating. Levels are calibrated.
Note DC on the ground will cause meter errors since it responds to DC.
My interface is fully shielded, I have installed clamp on ferrites on the audio cable and usb power cable, grounded the shaft of the range selector, and selected the best driver and receiver chips for lowest thd. I have also installed 0.1uF ceramic caps in selected locations. I have determined that the charger that came with my Samsung Galaxy S III smart phone is significantly quieter than the usb power even with the ferrites so I have ordered one of those.
The clamp on ferrites greatly reduced the common mode conducted noise from the PC. Previously the meter and indeed external meters indicated at least 7mV of noise which made setting low output levels impossible. (I'm designing a bunch of phono stages) The ferrites fixed this - now the meter indicates 00.0mV when no signal is input even on the 200mV range.
Based on the way the circuit is designed I recommend using floating mode only on the 200mV range with generator in ground mode, I still get much better results on all other ranges with the input grounded and the generator floating. Note that I can now get good results on higher ranges even with low amplitude input signals - that was not the case before.
Edit: I've added two graphs with the system acquiring 5mVrms input signals. And yes the Amber 3501 is extremely quiet - overall substantially better than the generator in my set up. (Note the consistent level of hum spectra relative to the noise floor at both 100mV and 5mV with the 3501A as the source.)
The sound card is an M-Audio 24192 running at 96k and 24 bits.
Note DC on the ground will cause meter errors since it responds to DC.
My interface is fully shielded, I have installed clamp on ferrites on the audio cable and usb power cable, grounded the shaft of the range selector, and selected the best driver and receiver chips for lowest thd. I have also installed 0.1uF ceramic caps in selected locations. I have determined that the charger that came with my Samsung Galaxy S III smart phone is significantly quieter than the usb power even with the ferrites so I have ordered one of those.
The clamp on ferrites greatly reduced the common mode conducted noise from the PC. Previously the meter and indeed external meters indicated at least 7mV of noise which made setting low output levels impossible. (I'm designing a bunch of phono stages) The ferrites fixed this - now the meter indicates 00.0mV when no signal is input even on the 200mV range.
Based on the way the circuit is designed I recommend using floating mode only on the 200mV range with generator in ground mode, I still get much better results on all other ranges with the input grounded and the generator floating. Note that I can now get good results on higher ranges even with low amplitude input signals - that was not the case before.
Edit: I've added two graphs with the system acquiring 5mVrms input signals. And yes the Amber 3501 is extremely quiet - overall substantially better than the generator in my set up. (Note the consistent level of hum spectra relative to the noise floor at both 100mV and 5mV with the 3501A as the source.)
The sound card is an M-Audio 24192 running at 96k and 24 bits.
Attachments
The future will be an USB 3 based ADC/DAC system....
or the ultimate would be a DIY project ADC/DAC, battery powered and feed the signal using a SPDIF I/O (feed using glas or fiber connection) to the digital sound card...
Hi Kevin,
I also had to combat common mode noise.
In my case it was the Murata converter inside the interface that put out high frequency common mode noise and not the PC. I tried separate supply that had transformer with separate pre/sec bobbins - Noise walked right through. I also tried to altered decoupling - Still noise. Finally, removing the Murata converter - No CM noise.
Kevin, I also have a lot of hum and noise on my SCIF. I added the 0.1 caps to all elco's, added a 12 uH smt between 5V input and fuse, and shielded everything, grounded the housing of all the switches, still only got about 10dB improvement. (Now at 115-120 dB quite a bit left to do)
I ordered some ferrite clamps for the external cables, so that will hopefully help, but I'm interested in your selection of the driver and receiver chips you ended up using. I also cannot null the meter, I have also about 7mV of noise, and cannot null the meter reading.
Interesting, or coincedance? I'm puzzzled why there are so many noise floors published south of 130dB, and I started at 100