196
Shortwave Broadcast / Voice of Nigeria 9690AM 1952Z 09 Sept 2018
« on: September 09, 2018, 1953 UTC »
S3-4, SIO 344; some minor fading. Overall good copy.
Shortwave Pirate Radio In North America And Around The World, And Other Signals That Go Bump In The Night
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197
North American Shortwave Pirate / Re: UNID 6930.17 AM 2011 UTC 3 Sep 2018
« on: September 03, 2018, 2029 UTC »
I can see the carrier in Frederick, but it's way down there in the S1 weeds for me.
198
Shortwave Broadcast / MWV Radio Feda 11965 AM 1953Z 03SEPT2018
« on: September 03, 2018, 1954 UTC »
Peaking to S2, but mostly down in the noise weeds. Can make out music and singing
199
Shortwave Broadcast / MWV African Pathways Radio 17640 AM 1804Z 03 Sept 2018
« on: September 03, 2018, 1805 UTC »
Can see a carrier and music occasionally pops up, but signal bouncing around S1. Amazing as short-wave.info has this as a 100kW transmitter out of Madagascar....
200
North American Shortwave Pirate / Re: UNID 6935.5 AM 0026 UTC 3 September 2018
« on: September 03, 2018, 0108 UTC »
S2 here...Charlie Daniels at 0107Z?
201
Equipment / impedence mismatch question
« on: September 02, 2018, 1559 UTC »
This is based off an observation i made trying to hook my H-800 directly into my afedri while on a road trip. The receiver's HF input is 50 ohm per the specs, and the H-800 uses RG-174 (50 ohm) so I didn't anticipate any problems. HOWEVER, the power supply box for the H-800 (the antenna probe receives power over coax from the box, and the connection to the receiver is on the box) uses RCA-type connectors for some reason while the afedri has those tiny SMA connectors. No problem i thought, since i have a spectrum of various adapters. So i hook everything up, with an RCA to F-type coupled to a F-type to SMA which is plugged into the afedri (I did NOT have a RCA to sma hence the workaround). Long story short..the receiver was deaf as a bat. Thinking there might be a problem w/ the H-800, i decided to rig up an improvised LOG using the RG-174 as it was the only coax i had. Still nothing...which was very odd considering i've had very good luck with LOG from that remote location before. The coax was visibly intact and had good conductivity between the ends. I finally considered the option that there might be an issue w/ the adapters and did an improvised connection (e.g. cut the RCA off the coax and directly made conductivity between the coax and the SMA connector on the radio) and BOOM! everything working great.
So...the adapter seems electrically fine in terms of conductivity. My working theory was that there was a problem with the 50 ohm-75 ohm-50 ohm mismatch between the coax, the adapters, and the radio. Does that make any sense at all? If so...why do i get OK results going from an antenna through 75 ohm RG-6 and into the radio with an F-type to SMA connector?
So...the adapter seems electrically fine in terms of conductivity. My working theory was that there was a problem with the 50 ohm-75 ohm-50 ohm mismatch between the coax, the adapters, and the radio. Does that make any sense at all? If so...why do i get OK results going from an antenna through 75 ohm RG-6 and into the radio with an F-type to SMA connector?
202
Equipment / Re: Grounding systems
« on: July 28, 2018, 1930 UTC »
UPDATE: OK I think i have the final plan. I'm going to add two more ground rods between the shack and the mains service entrance (so there will be one at service entrance, one at the shack entrance, and two in between (so about 20' between rods). I'll bond them together with 6 AWG Al wire, and the ground plate in the shack entrance box will be bonded to the ground rod there with 2" strap (or braid, whichever i can find). The coax from my LOG will go through a 75ohm surge protector/grounding block bolted to the ground plate in the shack entrance box. The coax from the LOG is buried for at least 40 feet before it makes a run across the back of the house, so i don't see much point in grounding it at its balun box (buried in the front yard).
Now, the AARL operating manual says to bond the RF bus to the AC safety ground and to bond everything together to the ac service entrance rod. Does this mean i need to also run a ground strap from the AC outlet I'll be using to my station ground? I think i recall seeing a powerstrip somewhere that had a connection for an additional ground.....
Now, the AARL operating manual says to bond the RF bus to the AC safety ground and to bond everything together to the ac service entrance rod. Does this mean i need to also run a ground strap from the AC outlet I'll be using to my station ground? I think i recall seeing a powerstrip somewhere that had a connection for an additional ground.....
203
Equipment / Re: Favorite coax for HF receive antennas ?
« on: July 19, 2018, 2305 UTC »
Thanks all. Will hit the internets and shop around this evening. Right now my radio is by the front door w/coax sneaking in through the screen door. Not a permanent installation.....
204
North American Shortwave Pirate / Re: UNID 6940 USB 2247 UTC 19 Jul 2018
« on: July 19, 2018, 2301 UTC »
Herbie Hancock Axel-F at 2259Z.
Wonder if there’s a loose connection or something? During previous music signal would go from S5 to QRN and right back again a second or so later
Wonder if there’s a loose connection or something? During previous music signal would go from S5 to QRN and right back again a second or so later
205
North American Shortwave Pirate / Re: UNID 6940 USB 2247 UTC 19 Jul 2018
« on: July 19, 2018, 2254 UTC »
Have it here too...was blasting clear and loud at S5 but has faded down to S2-3 as of 2252Z. Back at S5 at 2253.5Z. Playing w antenna?
206
Equipment / Favorite coax for HF receive antennas ?
« on: July 19, 2018, 2129 UTC »
I'm going to have to run something like 100'-120' ft of coax to get my LOG antenna connected to my radio room. Anyone have favorite versions of coax beyond RG-8/U, LMR-400/DMR-400, RG-6/U, and/or favorite vendors? It's for HF <15Mhz RECEIVE ONLY, direct (shallow) burial.
Thanks,
RF
Thanks,
RF
208
SDR - Software Defined Radio / generating waterfalls from rtl_power?
« on: June 12, 2018, 1534 UTC »
Hi all. I'm looking for mac software to generate waterfalls from rtl_power that are more interactive than some of the unix packages. The rtl_power software instructs a RTL-SDR stick to perform a power scan across a frequency band and log the data in a csv file:
(date, time, Hz low, Hz high, Hz step, samples, dB, dB, dB, ...). There are several ways to generate a heatmap from this data, but the ones i've gotten to work are all static...that is they generate an image file and you have to estimate the frequency of any 'blips' you see in the data, and you can't subtract out a background scan to account for computer noise and noise from the RTL-SDR itself.
Any suggestions? Thanks!
Robert
p.s. what i'd REALLY like to do eventually is have the RTL-SDR act as a reactive tuner for another SDR....
(date, time, Hz low, Hz high, Hz step, samples, dB, dB, dB, ...). There are several ways to generate a heatmap from this data, but the ones i've gotten to work are all static...that is they generate an image file and you have to estimate the frequency of any 'blips' you see in the data, and you can't subtract out a background scan to account for computer noise and noise from the RTL-SDR itself.
Any suggestions? Thanks!
Robert
p.s. what i'd REALLY like to do eventually is have the RTL-SDR act as a reactive tuner for another SDR....
209
SDR - Software Defined Radio / Today’s silly sdr question...rtl_power and SDRs
« on: June 03, 2018, 0217 UTC »
So bear with me...it’s my understanding that you can get a very broadband spectrum from a RTLSDR stick because rtl_power very rapidly samples a 2MHz chunk of spectrum and then moves to the next one and so on to the tune of ~80MHz/s. Shouldn’t it be possible to do the same thing with a higher end SDR (an Afedri, for example?). I’m surprised i haven’t seen this in any SDR software since it’s very useful for finding sporadic transmissions.....
210
Equipment / Re: Crossed Parallel Loop Antenna
« on: April 22, 2018, 2321 UTC »
Would it work stuck up against the side of a building, I wonder?
