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Messages - ultravista

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46
Josh, yes, I have a digital multimeter.

I noticed that on 80 and 60 meters, the loop is comparable to the active mini-whip for amateur stations in California, Arizona, and Northern Nevada - I am in Southern Nevada. So 'local' stations are pretty much the same but elsewhere across the bands, the mini-whip outperforms the loop 10 out of 10 times.

47
SDR - Software Defined Radio / Re: KiwiSDR antenna question
« on: January 15, 2019, 0319 UTC »
p.s. I am going to have some inexpensive fixed value matching transformers for sale shortly, suitable for LoGs and other antennas.

Count me in. How will you announce availability?

48
I bought a Palomar Engineers MLB-2 Long Wire antenna matcher (9:1) balun (100KHz-30 MHz). I'll use this once it arrives.

The coax is good, brand new in fact, but I'll try another one to test it.

49
The eaves are wooden, the wire stands off the wood by 1 inch (via ceramic insulator), and runs around the perimeter of the house.

There are some spots where the noise floor is higher while others it is lower.

Signals like WWV @ 5000 khz are strong with the active mini whip and nearly imperceivable with the loop. To me, it is very odd. I didn't expect such signal loss. It is almost like I do not have an antenna attached in HF.

50
I'd use both wires in the pair as a single conductor, but it'd be fun to see how the loop fared with two turns instead of just one.

I'll give the 'both pairs as a single conductor' a shot this weekend, in addition to a different connection from the coax to the antenna wire. The coax is new but my homebrew connector is about 15 years old. Heck, I should be able to use a clip to connect the conductor and ground to the coax to see what happens.

Not sure about the double run loop. Considering the second run of wire would be running parallel to the first run, wouldn't there be a coupling problem? It would be twice as long electrically but it will share the same stand-offs attached to the wood trip.

The mini whip power supply is in the shack (the dining room table ..) next to the radio and laptop. I have tried ferrites but it didn't seem to help, or at a minimum, had no material effect on the signals visible in the SDR waterfall.

The mast is 10 feet of galvanized steel fence post with a 10 foot section of PVC clamped to it (wooden dowel inside for strength). The active antenna sits at the top of the PVC.

What amazes me is that this little antenna in Las Vegas, NV is capable of receiving NDBs in Montana, Canada, and Oregon in addition to XSG, HLG, HLO, HLF, and HLW Coastal Radio markers when the conditions are favorable. Not bad if you ask me, but as a novice, perhaps something everyone can do.

The active antenna is great, awesome for me in fact, but I would like a working alternative to compare results. I was hoping the loop would be effective; sadly, it is not.

51
Equipment / Outdoor Under the Eaves Loop vs. Active Mini-Whip Antenna
« on: January 09, 2019, 1802 UTC »
I have been using an active mini-whip antenna (PA0RDT) at approximately 20 feet on a non-conducting mast. From my QTH, the mini-whip has been exceptional for RX.

Over the weekend, I ran a wire around the house under the eaves, approximately 200ft of wire @ 10 feet or more off the ground. As a loop, the coax braid connects to one side and the conductor to the other. It is two conductor alarm wire and I am only using one in the pair. No balun, just a simple PL-259 connector connecting the conductor and braid to the wire.

The mini-whip wholly outperforms the loop antenna. Strong signals present on the mini-whip practically disappear with the loop. On a scale of 1-10 for RX, the loop is a 1 or 2 compared to the mini-whip. Using the loop is like not having an antenna at all.

As a novice, I thought for sure, the long wire around the house would be at least as good if not better due to the electrical length. Not at all.

Can someone help me understand why the mini-whip @ 20 feet is outperforming the 200 foot loop @ 10 feet?

52
Josh, thanks for the thorough reply.

With my SDR and active mini-whip antenna here the SouthWest, I routinely and consistently can find STANAG and what I call FSK like signals with the 'twin towers' or left and right peaks. On any given day, I can find at least 20-30 similar signals and I would like to at least start somewhere.

With FLDIGI, MultiPSK, or Sorcer, I don't know where to start.

Decoding FAX and ACARS has been easy. The rest, not so much.

If you don't mind my asking ... which software do you use for decoding?

53
What can I use to identify digital radio signals to determine the signal type (FSK, MFSK, PSK, PSK31, STANAG 4***), then the Mode (LSB/USB), and Bandwidth to determine whether or not it is encrypted?

Knowing the details of the signal is the first step in decoding.

The question is for signals found outside of the amateur radio bands.

54
Spy Numbers / Re: UNID CW at 4870 KHZ
« on: January 06, 2019, 0218 UTC »
It looks like I resolved the problem .. removing VAC 4.51 and installing a different VAC application.
CW & NOAA images are working now.

55
Spy Numbers / Re: UNID CW at 4870 KHZ
« on: December 31, 2018, 1914 UTC »
Token, perhaps you can help ... if not, I understand.

I cannot get FLDIGI to decode anything decent. CW is a completed mess and WEFAX images are nearly impossible to read.

FLDIGI is configured for the VAC Line 1 and can 'see' the data streams from HDSDR when Windows 10 pipes the audio through VAC Line 1. This configuration appears to be working; however, the output of the FLDIGI decoder is gibberish.

In Windows 10, Line 1 (VAC) is the primary playback device - not recording device. FLDIGI is configured with Line 1 (VAC) for capture. When I change the SDR output to Line 1 (VAC), the waterfall display in FLDIGI does display the signal; however, it does not decode anything until I enable the Audio Repeater (KS - Kernal Streaming) for Line 1 (VAC).The VAC version is 4.15 (https://vac.muzychenko.net)

For example, CW is unreadable despite being tuned properly in HDSDR and FLDIGI. Squelch on/off doesn't matter - everything is trash.

The FLDIGI decoder becomes legible only if I enable the Audio Repeater (KS) that comes with FLDIGI. When running, the FLDIGI ouput appears to be correct. Validated with WEFAX and CW. In other words, FLDIGI only works properly with the Audio Repeater (KS) running; otherwise the output is trash. I though the Audio Repeater was to pipe the audio elsewhere post FLDIGI, not into FLDIGI.

My FLDIGI settings have been defaulted more than once and the VAC control panel is setup following instructions on the net.

Despite hours of fiddling around with nearly every setting, I still cannot effectively decode anything. I must have done something wrong.

Any ideas?

56
Spy Numbers / Re: UNID CW at 4870 KHZ
« on: December 31, 2018, 1843 UTC »
Interesting, thanks for the quick reply.

I am amazed with what this active mini-whip is receiving. Mine is the PA0RDT from Roelof Bakker himself. My neighborhood is noisy, lots of RFI everywhere and a suspected marijuana grower using crappy RFI producing ballasts. I theorize it is a grow light as it is on approximately 12 hours a day. When it starts, my SDR display goes wonky until it stabilizes in approximately 5 minutes.

Despite the noise, I am able to receive quite a lot with just the active antenna. In the AM, the NDBs like XSG Shanghai Coastal Radio come in strong.

Thanks again for the feedback, I'll check your logs.

57
Spy Numbers / Re: UVB-76 "The Buzzer" mixed with odd digital signal
« on: December 31, 2018, 1821 UTC »
Token, are you able to receive the buzzer @ your location? We're pretty close (CA - NV) but I am unable to find the buzzer using an active mini-whip @ approximately 20ft.

I am on your SDR now and hear CODAR @ 4625. I too pickup several CODAR 'stations' here in Las Vegas, in the AM and PM. I suspect the stronger CODAR signal competes for the weaker buzzer.

58
Spy Numbers / Re: UNID CW at 4870 KHZ
« on: December 31, 2018, 1815 UTC »
Token - how did you determine the RIS9 callsign? I assume you too are able to receive this station?

Do you run the audio through a program or just know Morse well enough?

59
Spy Numbers / UNID CW at 4870 KHZ
« on: December 31, 2018, 1654 UTC »
UNID CW at 4870 KHZ received most mornings in Las Vegas, NV.

Didn't find much on the net other than references to M89 Chinese Military. When I am able to receive this unknown CW station, Asia SW stations are also very strong.

I am unable to decode the CW - can't figure out how to get HDSDR, FLDIGI, and the Virtual Audio Cable to play nice to decode anything. Something with my configuration is wrong as I can't decode anything despite being able to see it in the tools. If anyone is willing to help, I will sure appreciate it!

Anyone know what/who is broadcasting CW @ 4870 KHZ?

60
Equipment / Re: Some more LoG (Loop on Ground) results
« on: December 24, 2018, 0141 UTC »
Are either loops amplified or run straight to the radio?

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