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Messages - IQ_imbalance

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196
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.....


197
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.....

198
Herbie Hancock Axel-F at 2259Z.

Wonder if thereís a loose connection or something?  During previous music signal would go from S5 to QRN and right back again a second or so later

199
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?

200
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

202
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....

203
So bear with me...itís 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.  Shouldnít it be possible to do the same thing with a higher end SDR (an Afedri, for example?). Iím surprised i havenít seen this in any SDR software since itís very useful for finding sporadic transmissions.....

204
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?

205
Equipment / Re: Electronic Dog Fence Wire as Antenna
« on: April 22, 2018, 0132 UTC »
Just discovered an invisible pet fence installed by the previous owners of my house. I'm going to check for continuity, but if its still in one piece I'm going to see what happens when used as a "Loop UNDER ground" antenna....

206
Just for peoples' amusement. On the left, the parallel tuned wave trap for 820kHz.  On the right, the series tuned wave trap w/ an adjustable coil.  Neither did much, if anything  ::)

207
Well my first attempts at building notch filters left much to be desired. Tried a series tuned wave trap w/ a tunable coil and a parallel tuned wave trap specifically for 820 kHz.  Didn't see any attenuation, either alone or in combination w/ my BCB high-pass filter.  Could be the cheap Amazon components (fixed value inductors & capacitors), could be my questionable wiring skills, could be the antenna is boosting the broadband signal coming in to a point where i can't notch it out.  Oh well... I don't think i'll quit my day job just yet. 

208
Clandestine Stations / Re: Denge Welat 7320 AM 2131 UTC 21 Feb 2018
« on: February 24, 2018, 1711 UTC »
I'm basing the ID off the SW schedule Chris provides in DX Toolbox.  Looking at the transmitter location in DX Toolbox and for Radyoya Denge Kurdistane (from Short-wave.info) it looks like a match for location and frequency.....

209
Shortwave Broadcast / R.VERITAS ASIA 15355kHz 2209 UTC 21 Feb 2018
« on: February 21, 2018, 2209 UTC »
Way down in the weeds (S2-ish).  Able to catch a word here and there. 

210
Clandestine Stations / Denge Welat 7320 AM 2131 UTC 21 Feb 2018
« on: February 21, 2018, 2135 UTC »
Signal down in the S2 range; can barely make out words.  No music....

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