Search found 17 matches

by Scannerz
Sun Jun 17, 2018 10:39 pm
Forum: Spectrum Analysis
Topic: Spectrum Analyser - screen dumps
Replies: 12
Views: 2343

Re: Spectrum Analyser - screen dumps

The 2mhz High Pass test....forgot again.
by Scannerz
Sun Jun 17, 2018 10:37 pm
Forum: Spectrum Analysis
Topic: Spectrum Analyser - screen dumps
Replies: 12
Views: 2343

Re: Spectrum Analyser - screen dumps

Using a quick build cheap noise source circuit I found on the net, I ran a quick test of a 2mhz homemade High pass filter. The transistors I used were SS9018 vhf/uhf npn. The Noise circuit did not require any attenuation and I think it only draws 0.35mA at 9v. And goes up to about 500mhz. Noise circ...
by Scannerz
Fri Jun 01, 2018 11:21 pm
Forum: SDR Antennas
Topic: Cheap broadband planar elliptical dipole antenna
Replies: 7
Views: 2013

Re: Cheap broadband planar elliptical dipole antenna

In relation to F1BJB comments about the yagi are correct. So after some thought I figured that the extra reflector for the yagi is helpful for my use with a preamp (lna4all). The amp is adding 16 to 18db extra gain for the yagi`s designed for 1000mhz to 1600mhz. So I`m basically redirecting the adde...
by Scannerz
Sun May 27, 2018 12:07 am
Forum: SDR Antennas
Topic: Cheap broadband planar elliptical dipole antenna
Replies: 7
Views: 2013

Re: Cheap broadband planar elliptical dipole antenna

Maybe you are right though even without the extra reflector the yagi performs very well on L-Band. Yagis can receive from the back end though obviously its going to be poor. As I try to think outside the box i thought i`d give it a try. The yagi designs where done with this free program from John Dr...
by Scannerz
Fri May 18, 2018 10:05 pm
Forum: SDR Antennas
Topic: Cheap broadband planar elliptical dipole antenna
Replies: 7
Views: 2013

Re: Cheap broadband planar elliptical dipole antenna

Thanks Phil,
I have made some other small/simple improvements to other antennas.
One was adding an extra square plate Reflector to a 15 Element yagi for L-Band Aero signals.
Which in turn gave an extra 6dbi (One S point) increase in signal strength.

Picture included...

Tony from VK3.
by Scannerz
Thu May 17, 2018 5:47 am
Forum: SDR Antennas
Topic: Cheap broadband planar elliptical dipole antenna
Replies: 7
Views: 2013

Re: Cheap broadband planar elliptical dipole antenna

Forgot to add the links.... the goldern ratio oval https://www.blocklayer.com/oval-templates.aspx Also has lots of other interesting printable templates, rulers,star,cones =(thinking of discone base here) Also the larger the oval/disk the lower the frequency transmission starting point. ...............
by Scannerz
Fri May 11, 2018 11:18 pm
Forum: SDR Antennas
Topic: Cheap broadband planar elliptical dipole antenna
Replies: 7
Views: 2013

Re: Cheap broadband planar elliptical dipole antenna

SWR chart for the antenna using rigexpert 1400 overclocked to 2800mhz.
Readings from 1400 to 2800 are not realy supported though should be pretty close.
cheers Tony.
by Scannerz
Fri May 11, 2018 11:14 pm
Forum: SDR Antennas
Topic: Cheap broadband planar elliptical dipole antenna
Replies: 7
Views: 2013

Cheap broadband planar elliptical dipole antenna

Cheap broadband planar elliptical dipole antenna. The antenna consists of two ovals (Goldern Ratio) disks Inner of the coax goes to the top disk, Braid of the coax goes to the bottom disk. Each of the ovals dimentions are 335mm x 207mm Short length of RG58 or LMR195 would be ok for connection to the...
by Scannerz
Sun May 06, 2018 10:36 pm
Forum: SDR Antennas
Topic: Discone Antenna
Replies: 6
Views: 2368

Re: Discone Antenna

Hi, I`m planning to post shortly details of an antenna I have developed that you will be able to transmit on (146mhz) and anywhere between 250mhz to 2800mhz with an SWR of around 1.5:1 throughout the range. Will receive 118mhz to 2800mhz or greater. This based on a dipole so it has increasing gain i...
by Scannerz
Wed Jan 18, 2017 8:46 pm
Forum: SDR Antennas
Topic: RA0SMS Miniwhip bad performance on SDRPlay
Replies: 36
Views: 24505

Re: RA0SMS Miniwhip bad performance on SDRPlay

Went back to my original setup for reference ,8mhz and 14mhz dipole (V for 14mhz and inverted V for 8mhz)with 1:1 balun and a MFJ-945D mobile tuner. And this of course allows me to cover all HF freqs very well and not surprisingly better than this mini-whip. Will experiment a little more with my set...

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