Servo Magazine Issue worth buying and/or reading plus back to work on the telescoping yagi

Finally got around to working on the telescoping yagi that I think the spreadsheet I had was on the computer(s) in the mobile office Ford F150 that was stolen in Utah. I think I wrapped up the min and max specifications with the different telescopic antennas I have related to the min and max boom specifications.  I also decided to make an adjustable "U" matching network element or "hairpin" and need to buy two nylon 10-24 1/2" thumb screws.  I think that will take care of everything other than the modification of the antennas where I need to drill out a little larger for 6-32 or equivalent wood/sheet metal screws as well as the reflector antenna trimming down about 3/8" I'm thinking... though might not be critical since a receive antenna only.  Then again, I want to maintain the director, driven and reflector element ratios for optimal performance in the the ~440MHz range max Hz with a calculated new ~110MHz min Hz.


I've been working on recreating the spreadsheet and will post... though looks like I can't upload unless I create into and image that can be renamed.  I'll look into that next.

Here is the Servo Magazine worth reading into regarding radio/audio direction finding.  I was going to crop out the wideband spiral conical antenna for ISM WiFi with ground plane and impedance matching piece... though figured I'd show. 









Comments

Post a Comment

Popular posts from this blog

Ultrasonic Projects and others

Image
I was looking into the latest and greatest microphones, ultrasound microphones and detecting ultrasound in general more real time spectral analysis since I was thinking about modifying the Mini-3 Bat Detector to perform a more automated sweep versus just turning the variable capacitor. Well, I found this interesting video that's inspired me to add an antenna connector onto the Mini-3 Bat Detector or just invest in one of the Franzis systems this gentleman is using in the video: In regards to sonic range recording and maybe getting into the ultrasonic range... there is this build that has some great info regarding the most cost effective lowest noise mic on the market, the Rode NT1-A Studio mic: If you read into the above videos description link, the authors note the amplifier might be good above 100kHz also. Here is the screenshot from the above video of the schematic noted used: See here for above video reference:  https://sound-au.com/project66.htm In regar
Read more

Electronics and RF Engineering Projects - Spectrum Analyzer Adapter for Oscilloscope

Image
Wanting to document here one of the first systems that I invested in for remote sensing and remote transmission detection, i.e. the TDS-520.   In order to utlize the TDS-520 as a spectrum analyzer other than the digital FFT function and 500MHz plus bandwidth for quicker reviewing to identify peaks correlating with sound or other bio-metric or perimeter sensors... I decided I'd try to make a spectrum analyzer adapter as I think this will be a good project or set of projects to focus on.  Especially, I'm thinking this will be a good exercise to solidly concepts for ultimately learning more to be able to make modules for the TDS-8000. Here are the references for starters: Two plans regarding a spectrum analyzer adapter for an oscilloscope and thinking about using more modern modules with an MCU also. Any suggestions? See the last two referenced links in the link below for design plans (see pg 42 in the last link which is actually pg.41 in the publication): https://randys
Read more

Detection Antenna Update: Spiral Conical Antenna Design

Image
https://www.facebook.com/photo.php?fbid=3675555835839525&set=a.1586822128046250&type=3 Inspired by the University of Illinois  antenna designs and SuperKuh  more improvised design along with some other references I found online when searching Google images, I decided to make a ~400MHz to 1GHz+ range spiral conical antenna starting with single and double bottom fed designs like Andrew McNeil' s spiral conical design videos and then a double top fed design like SuperKuh using household electrical wiring since I have some.  Some reference feed-line connector and math dimensions to consider (Note: update with better image with wavelength ratio specs), though for the bottom fed design I'll refer to Andrew McNeil's design beginning with a non-log spacing design.    Another design to consider for a final antenna with consideration regarding polarity where two antennas have a right hand polarization and two have a left hand polarization so to encompass
Read more