Rune I made a recording of what you sounded like on the night of March 15 (UTC) in California. My receive antenna was nothing special - just some unknown combination of my transmit antenna (55 ft top
On 9/13/2019 6:31 AM, N4ZR wrote: I don't think I've ever read anything on this topic. Basically, what I'm asking is, could ground wave to a fairly nearby Skimmer be used as an analogue to low-angle
During the last minimum, there were times when high northern latitude stations in zone 17 and 18 would be very strong for long periods of time here in southern California. Last Sunday morning during
Thanks for coming back to me, Tom. The only reason I knew the band was open is that I was sitting on 1821.0 listening for S01WS who had been spotted there. Apparently he was gone because, Eric NO3M,
Recently I've been discussing common mode chokes with others who have a different methodology. They prefer to do a transmission test through the choke and report the "common mode rejection". This is
I was hearing them 339 to 559 this evening around 0730 UTC. I may have actually worked them. I could tell they came back right away when I called them, but the QSB buried their reply. After a couple
What matters is the signal-to-noise ratio (SNR). Take the canonical example of an ideal 2-port Wilkinson power combiner with in-phase coherent signals of 10 Vrms applied to each input along with 1 Vr
Hi Lee, Yes, if you are combining coherent signals that are not in phase, then the each of the voltage vectors is weighted by cos(phi-i) where phi-i is the angle between the i-th voltage vector and t
There are a lot of SMT to DIP adapter boards out there which would allow newer SMD op-amps to be used in older through-hole PWB layouts. https://www.digikey.com/product-detail/en/aries-electronics/LC
I agree with your conclusions regarding the case of isotropic atmospheric noise. This is the same reason that cold space looks like 3 Kelvin regardless of how high the antenna gain. As the antenna ga
Steve, Couple of questions to rule out gain distribution issues: 1) On the sense antenna input do you have the pre-amp turned on or off? 2) Is your sense antenna intrinsically inefficient like a beve
Another pitfall that you have to be careful to avoid with the MFJ-1026 is making sure the level of the QRN you are trying null that is coming out of the sense antenna isn't much lower in amplitude th
Hi Mike, Yeah, when the off-air noise floor is a lot higher than the thermal noise floor from the JFET pre-amps, the imbalance I was alluding to wouldn't typically impact the overall noise floor sinc
Dave is that -112 dBm you calculated the output referred noise? If so, what is the gain behind it? Thanks, 73, Mike W4EF....... 1.8 MHz, 50 nV/Hz^0.5 7.0 MHz, 26 nV/Hz^0.5 14 MHz, 19 nV/Hz^0.5 28 MHz
I just happen to have a spare MFJ-1026 at home. I did a real quick test using my FT1000MP MK-V while powering the MFJ-1026 from an Astron supply. Similar to your results, Steve, I got about a 12 to 1
You were spot on, Dave. Thanks for the suggestion. I rechecked the numbers this morning and the AUX (i.e. sense antenna path) gain varies about 2dB as a function of where the phase control is set. It
Hi Mike, I was trying to address the particulars of N2IC's situation which involved the higher HF bands (although at this point in the sunspot cycle, perhaps I should have included 20 meters). Readin
Roger, When you checked for increased noise on 10 and 15 meters, did you have your radio set for maximum sensitivity and were the main and AUX input ports of the MFJ-1025 terminated with 50 ohms (or
Dan, Reading that QRZ.com thread you linked to and reflecting on K4SAV's measurements and how much they appeared to vary over a fairly short period of time, got me wondering about what could be respo
I heard JH4UYB on Sunday morning calling CQ on SSB with a good signal, but he couldn't copy me. I believe he was operating above the FT8 segment, but I don't recall his exact frequency. 73, Mike W4EF