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by Mike2459
Sat Jun 08, 2019 5:41 pm
Forum: Spectrum Analysis
Topic: AD9850-ARDUINO Interconnect
Replies: 16
Views: 2686

Re: AD9850-ARDUINO Interconnect

I've done it both ways.
by Mike2459
Sat Jun 08, 2019 5:21 pm
Forum: SDR Antennas
Topic: New Sdrplay and antenna creation
Replies: 21
Views: 2367

Re: New Sdrplay and antenna creation

This fellow at MIT says it is smaller and that the other plate is infinity.

Earth.JPG
Earth.JPG (194.9 KiB) Viewed 242 times


http://web.mit.edu/sahughes/www/8.022/lec06.pdf

An interesting read that might have some clues.


Mike
by Mike2459
Sat Jun 08, 2019 4:38 pm
Forum: SDR Antennas
Topic: New Sdrplay and antenna creation
Replies: 21
Views: 2367

Re: New Sdrplay and antenna creation

Enoug to say that, if the above is correct, increasing the SURFACE of the PC board devoted to the "capacitive coupling" should increase the antenna output, It does increase the output. But the relationship between surface area and output is non-linear. That is, if we double the area the o...
by Mike2459
Sat Jun 08, 2019 3:10 pm
Forum: SDR Antennas
Topic: New Sdrplay and antenna creation
Replies: 21
Views: 2367

Re: New Sdrplay and antenna creation

The plate or wire has capacitance but where is the other half of that capacitor's plate? Plate or whip Most active electric field antennas do not, like the MiniWhip, use a metal plate, but a whip of about a meter long. This makes no essential difference for the operation. Such a whip will, if it is ...
by Mike2459
Fri Jun 07, 2019 9:00 pm
Forum: SDR Antennas
Topic: 6 Meter 50 MHZ Transoceanic Skip
Replies: 0
Views: 127

6 Meter 50 MHZ Transoceanic Skip

Just heard EA2XR -16db ((near Bilbao, Esp.)) in FT-8 transmission into midwest US.

Using jury rigged attic loop antenna into old Ameco preselector feeding an RSP-2
by Mike2459
Fri Jun 07, 2019 8:13 pm
Forum: SDRuno
Topic: RECEIVE DATA OUTPUT FEATURE SUGGESTION
Replies: 11
Views: 682

Re: RECEIVE DATA OUTPUT FEATURE SUGGESTION

I was going to try to do a CSV. When I went to change the time mark interval, I inadvertently changed FFT average instead. I thought something was strange when I saw 32 as one of the choices. Who would want to use 32 seconds as a time-mark interval :)

Maybe, this also happened with you.
by Mike2459
Fri Jun 07, 2019 6:55 pm
Forum: SDR Antennas
Topic: New Sdrplay and antenna creation
Replies: 21
Views: 2367

Re: New Sdrplay and antenna creation

It hasn't been confirmed but it's been suggested that the problem with the RA0SMS is that it uses a MOSFET. The PA0RDT uses a J310 JFET. They are both field effect transistors but MOSFETs generally have much higher input impedances and higher input capacitances. The antenna in question may have been...
by Mike2459
Fri Jun 07, 2019 6:06 pm
Forum: SDR Antennas
Topic: New Sdrplay and antenna creation
Replies: 21
Views: 2367

Re: New Sdrplay and antenna creation

Bakker got his units wrong in the text. The units in the text should be millimeters (mm) not centimeters (cm). The units used in the table are correct.
by Mike2459
Fri Jun 07, 2019 5:38 pm
Forum: SDR Antennas
Topic: New Sdrplay and antenna creation
Replies: 21
Views: 2367

Re: New Sdrplay and antenna creation

In response to Glovisol: You wrote on May 31, 2019: "The shape and the size of the surface of the antenna PC board seem to be "magic " in the sense that, as soon as you alter these dimensions, the antenna does not work any more" I don't know where you got the idea that altering t...
by Mike2459
Fri Jun 07, 2019 4:06 pm
Forum: SDRuno
Topic: Feature request
Replies: 3
Views: 472

Re: Feature request

I spoke too soon, you are correct - this doesn't work for FM and it's submodes

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