Messages

31

SDR - Software Defined Radio / Re: RX-888 and graphic board

« on: March 02, 2023, 1749 UTC »

Some considerations on the RX888 and cuda/open cl offloading/cpu time;
One is only certain video card make and model/driver/os can take advantage of gpu offloading in sdrc.
Another is I am pleasantly surprised at Kris' laptop getting as good results as it does with open cl enabled.
Yet another is last I heard the maker of the RX888 is working on a RX999, mebbe that one has a fpga?

I tried some while back with windows 7 on a 4 core cpu and a Nvidia Quadro 2000 gpu and no go on cuda doing the work as the cuda version in the driver, the latest driver made to support the Quadro 2000 in that system, was too old for sdrc so no gpu offload for me.

32

The RF Workbench / Re: Redhat's LULU build attempt

« on: March 02, 2023, 1734 UTC »

Was anyone else thinking rh was gonna drill his hand?

33

Equipment / Re: Made in China Wellbrook 1530 Loop Antenna?

« on: March 02, 2023, 1727 UTC »

The MLA-30 uses a cheap video preamp among other defficiencies. It can work okay for casual listening, but I would suspect some type of issue like maybe a very high noise floor if seemingly performing anywhere near a decent active loop like a Wellbrook, W6LVP, DXE RF-PRO-1B, or even MFJ-1886.

Yeah well spotted.  It brings me the memories of those moments when I had the same thoughts on MLA-30 actually.   It was ok for general strong stations SWL BCLing, but it had never pulled the rare challenging DX such as the QRP AM stations from Brazil and all around South America, Africa or Pacific Ocean.  It definitley worked, and worked OK.  But it wasn't excellent DX puller for sure.   But then the youtube comparison between MLA-30 and WB 1530 seems to be giving ideas that those 2x antennas are in similar level.   Testings done during the day time for strong stations not too remote locations cannot really tell the clues actually.  He should have tried copy Radio Tarma from Peru, or some Middle and South American low powered AM stations at nights - and then the winner would be clearer?

Don't forget loops can be directional; if not oriented to favor the target region you're not going to see sigs you might otherwise. Also, festooning the coax with ferrets (ferrites) will help isolate the loop from the coax influence on gain and directionality. Of course if you lay it flat you get a horizontally polarised omnidirectional pattern. I am considering two loops, set to favor euros and asiatics. An azimuthal map based on your location might help in aiming antennae if you want to cover specific regions.

https://ns6t.net/azimuth/azimuth.html

34

QSLs Received / Re: LRA36 RN Arcangel eQSL

« on: February 23, 2023, 1900 UTC »

Neat!

35

Huh? / Re: Read this and tremble...

« on: February 23, 2023, 1900 UTC »

This fearsome penguin is what inspired the ruskiis to develop shkval!
https://en.wikipedia.org/wiki/VA-111_Shkval

36

Equipment / Re: Recommendations for a Hiking Antenna

« on: February 23, 2023, 1853 UTC »

Some wire laid out on the ground can do for mobile/pedestrian rx ops. Easy to pay out and reel in, if long enough it even will exhibit some directionality, long enough here meaning a half wave or so to the tuned freq.
No power needed.

37

Equipment / Re: Made in China Wellbrook 1530 Loop Antenna?

« on: February 23, 2023, 1850 UTC »

After watching this https://www.youtube.com/watch?v=6PTu0g5W9do I have the feeling dual crossed MLA30s (with 1 meter copper wire or tubing as modded in the vid) would be a better setup at about half the price of the chicom knockoff. I suspect there will be unit-to-unit performance variations on MLA30s but you can adjust the gain of the thing with the internal pot.

Wow, MLA-30 is not much different from Wellbrook 1530 in performance from the video (apart from LW, and the top band of Ham radio), and it is about  1/6 - 1/8 price of Wellbrook.  It seems the best value for money commercial HF RX active loop antenna?  Great video by the way, thanks for sharing.

Yeah what I was thinking. The part that makes me wonder is why it's deaf on 160m. Still seems like a good deal for the cost on the rest of the bands.

38

Huh? / Re: Biden visit Ukraine 20 Feb 2023

« on: February 20, 2023, 2139 UTC »

Callsign SAM060.

39

The RF Workbench / Re: Redhat's LULU build attempt

« on: February 20, 2023, 2123 UTC »

I took one look at your bench and felt right at home lol.

40

Software / Re: JSquelch

« on: February 20, 2023, 2100 UTC »

Thanks for the link, also his work on psk31 was amazing.

41

SDR - Software Defined Radio / Re: Ukraine Uses Off-The-Shelf Electronics To Target Russian Communications

« on: February 20, 2023, 2017 UTC »

Good luck taking down a dji drone with himars or mortars and I doubt they can see the drone operator who is likely in a ditch somewhere safe. Better to use a drone zapper gun, they have a high gain log-yag antenna and fire wifi and gps noise at a drone so it drops to the ground in confusion, just have to know where they are first. They look like the guns in starship troopers.

42

SDR - Software Defined Radio / Re: Recording to a hard drive--SSD or HDD?

« on: February 20, 2023, 2010 UTC »

I would consider either an enterprise class hdd or a laptop drive. Both are hardy, the laptop drives will likely use least amount of power and produce less heat, the enterprise drive will likely last longer and have better performance and also commands a higher price going by capacity, but a laptop disk spinning at 5400rpm should do just about all one wants and that is what I use as sdr save drive. The laptop drives are also tiny, if size factors into the criterion.

43

Equipment / Re: Using ATU with SDR or Portable Radios?

« on: February 20, 2023, 1952 UTC »

Project IC-R71A recently made me deploy a GROVE TUN-3 Minituner for the first time in years. All I wanted to do was some quick ad hoc testing on the R71A, string a few feet of wire over a window frame and see how well the combo did.

The TUN-3 is a simple passive device, you have two controls, one sets the range and the other tunes. Have to say it wrung every drop of rf outta that 8ft piece of wire, amazing. Of course these work best below about say 15MHz but they can still help in keeping undesired rf out of the system, the lower the freq the better the q I suppose. I don't recall the Drake R8 I last used the TUN3 with as having so profound effect on me, but that was with a 70ft sloper from the second story down to the mailbox at the end of the driveway, much more rf to begin with in the R8/70ft sloper/TUN-3 setup than what one gets from 8ft of wire strung over a window sill feeding an R71A. The mail folks thought the sloper wire to the mailbox was for earthquake detection, heh.

Order a Grove TUN-3 MiniTuner today!
https://worldradiohistory.com/Archive-Monitoring-TImes/Grove-Catalog/Grove-1989-02.pdf
Also be sure to check out the new Fabulous Grove SR1000 Professional Surveillance Receiver! ! !

 I wholeheartedly recommend any suitable atu device for rx use when one wants to focus on a specific channel. And by suitable I mean one with manual controls. Most any new or used manual  HAM  transmatch will do, however don't expect the HAM models to tune below 1.8MHz, a lot of them only go down to 3.5MHz, so one made specifically for rx use would be best suited for lower freq excursions.

Or build your own;
https://aa7ee.wordpress.com/2021/03/23/a-passive-tunable-hf-preselector/
https://www.eevblog.com/forum/rf-microwave/lets-start-a-project-to-build-an-hf-preselector/
https://www.robkalmeijer.nl/techniek/electronica/radiotechniek/hambladen/qex/2003/03_04/page45/index.html

44

Equipment / Re: Made in China Wellbrook 1530 Loop Antenna?

« on: February 20, 2023, 1904 UTC »

After watching this https://www.youtube.com/watch?v=6PTu0g5W9do I have the feeling dual crossed MLA30s (with 1 meter copper wire or tubing as modded in the vid) would be a better setup at about half the price of the chicom knockoff. I suspect there will be unit-to-unit performance variations on MLA30s but you can adjust the gain of the thing with the internal pot.

45

Utility / Re: 11039 (BFO) BFSK T-600 BEE/50/200

« on: February 20, 2023, 1848 UTC »

19688(cf) RIT Severomorsk T600/CIS-36-50 50Bd 200Hz Shift 20FEB23 1725Z

1D 0C 12 02 12 13 12 19 _16 0E 11 1E 0A 0A 1C 1D 03 0A 1B 06 0C 02 18 08 21 1F 0
9 ___19 _0F 19 05 03 0B 01 ___1E 21 0D 08 1D _09 _0F ___16 1F _0D 12 09 _0B 0A 1
E 01 _01 18 _06 __21 1D 15 0A _14 1B __0D __16 _21 _0F 0A 1B 1F _0E 00 __1C ___1
1 0C 17 08 10 04 15 1B 1A 0E ____00 _08 1D 18 _21 1F 1D 22 1B ____18 05 _1C __09
 17 _00 _0C _1E 18 10 18 1F 0F 16 09 __1E ____0F __11 _17 0D _21 08 1D 11 21 _17
 05 __0F 04 __00 1D 11 _____09 08 00 0E 00 19 21 17 19 13 __14 _04 1A ___1B 07 _
19 _03 03 _04 0F 1E __01 14 0E _17 _____18 12 0C 12 13 12 0C 12
[END OF MESSAGE]
12 18 12 10 03 0C 12 06 _13 12 ___12 _12 _12 ___12 _12 18 0D 12 0C 12 05 12 1A 1
2 ___12 __0D 12 13 12 0D 0F 0D 12 _____20 _12 _12 ___1E 09 21 1B 18 1C 17 12 _17
 04 ____10 19 06 1A 04 1A _01 __18 03 06 09 08 04 _0B _0B __0B 1C _05 ___18 07 0
E 1F 21 08 _06 01 __12 07 0F _19 11 1A _0C 1F _0F 02 16 1A 19 08 19 04 0F 05 _17
 _18 01 _02 02 ______1E _22 22 12 09 _12 0D 12 1B 12 13 12 0D 10 0D 04 0D 0B 18
00 13 _13 __12 0D __12 ___00
[END OF MESSAGE]