" All of us have tried separate small loop receive antennas, both passive and active, with only marginal improvements. Noise cancelling antennas don't work due to the myriad of noise sources in built
Tom is right about this thread splintered. It is bugging me to hear several very common misconceptions going on for years. 1- A preamp is part of the radio, not the antenna. As such, when you add a p
Art I don't know where this coming from ,but the gain you need for a VWF modest size is 20db for vertical polarization and for horizontal HWF you need 40db on 160m, on 80m divide this by 2, you need
At -140 dBm and 250 Hz noise bandwidth, the system would require a 1 dB noise figure front end. That's about 35 deg K noise temperature. Tom is as usual 100% right, the RX system gain should be near
Andrew Very interesting, that is my presentation, but my updated early terminated loop reference was from Harold H. Beverage patent applied 1938 and issue 1941 owned by RCA U.S. Patent 2,247,743 Jul
"" A similar observation was made 20 years ago by Brian Beezley, K6STI, in a QST article titled "A Receiving Antenna that Rejects Local Noise" (September, 1995, page 33): I've been looking around for
Jim The concept of horizontal dipole is just a name for a wire parallel to the ground. If you change the description from TOTAL Field on EZENEC and use Horizontal and Vertical field your results won'
A 0.5 dB noise figure front end amplifier with NO other losses would produce -149.5 dB MDS. That is the absolute maximum MDS sensitivity obtainable with 250 Hz BW and 0.5dB total input noise figure.
I meant OFF and not ON for the internal preamp. I don't use internal preamp ON. The issue is most internal preamps are not designed for 160m, they need to cover up to 50 MHz Even the ICOM Norton prea
Lee Yes, this is confusing as it can get. Any passive component adds noise, any active components adds noise. Power noise, and you only can add power noise converting it in equivalent temperature in
Hi guys I would like to add my 2 cents on this matter. If you not good, or a very good, RF engineer it is hard to understand what DDU/DUC radio do for you. The most important thing, DDC/DUC radios ar
Hi Filipe Zero , you should use material #31 or #77 , The core you have is not good for low bands. JC N4IS --Original Message-- From: Topband [mailto:topband-bounces@contesting.com] On Behalf Of Fili
Hi Felipe It works like a voltage divider where the impedance to ground should be lower as possible to give you more attenuation like 1k/500ohms versus 1K/5 ohms divider. You should use the choke nea
Hi Guys It's well know the ability to copy weak signal near strong carriers. I run a QS1R using HDSDR all the time shearing the same RX antenna with my IC7800. In the last 10 years only once I worked
<< What do we do with them?>> We do what we are! Gentlemen ! giving always a good example. Even almost 40 year later worth reading W1BB. GENTLEMENT BAND!!??? --Shall stress the importance of keeping
Hi folks I would like to add some comments to receiving antennas issue. Any resonant thing (wire, cable, rotor cable tower, TX antenna...) will interact with the RX antenna if they are in the same po
"When you say "NOT work", you probably need to specifically list the diminished performance attribute due to more conductive media underneath." The issue with horizontal wire and the ground is the fa
<<RHR is just another form of progress due to advances in technology, if we did not embrace progress in ham radio technology we would all still be talking to one another on Lunch boxes and Gooney box
card if the DX QSO occurred in the middle of the day since the path would be impossible. Can't make that assumption, anymore.<<< LOTW is responsible for 90% or more 160m DXCC confirmation and there
problem this year, as articulated in VE3ZI's post, is that there are/were several DXpeditions out this weekend with operations on 160M that should have been protected from QRM. << I would like to sa