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Archive for the ‘Antennae’ Category.
I bought used outdoor WiFi access point for couple of coffees. At first I wanted to use only the housing for conversion of the TTN Indoor gateway to outdoor gateway. But after some testing and factory reset of the AP I found out it is working and could be configured as stand-alone WiFi MIMO AP. Usually such APs require infrastructure, or at least some management server.
“Special offer” came out for 5GHz antenna. It was posted on Polish web store Interprojekt, where I sometimes buy some equipment for long range WiFi point-to-point links.
The antenna came well packed in carton with additional box for the feed. The grids were separated with paper to avoid scratches during transport.
This simple Helical Antenna can be used for most LoRa (and other small wireless device) applications, where space constraints exist. The construction is simple, made from wound solid Ag plated copper wire taken from piece of coaxial cable.
Helical axial antenna for 868MHz
Two options how to use this antenna on the PCB modules
Continue reading ‘Small “rubber-ducky” helical antenna for 868MHz’ »
This is simple antenna for 868MHz built in 5…10 minutes. Take about 10cm of RG214, a plate of PCB with the copper at one (or both) sides. Remove the coax shield and inner dielectric on one side in length of about 85mm. You will cut this to proper length during SWR measurements.
Simple antenna made with piece of coax and piece of old PCB.
Continue reading ‘Quick and dirty 868MHz antenna in 5 minutes’ »
This is description of coaxial collinear antenna for 868MHz applications. I designed this for Lorawan gateway.
Antenna tested with lorawan gateway
Continue reading ‘Collinear antenna for 868MHz Lorawan Gateway’ »
This is complete project for 1×6 antenna switch. It was bult in more than 50 pieces around the world and performs really good. Even big guns use it for their systems. The project was designed with help from other OMs (S55O, S59MA, S50LD, S51CT, S51ZJ, SM2WMV/SJ2W and others).
6×1 antenna switch
Do you ever wondered how much magnetic field garbage is around you? This is cheap and easy build to measure magnetic noise or to compare which switching supply is more sh*tty.
Near field probes are nothing new. It’s easy to find one via web search. Here is one good reference for H and E field probes which I found via google image search:
EMC near field probes for H and E field
Branko, one of the famous experts for old(ish) radio devices designed magnetic loop antenna, which can be 3D printed. Here are complete instructions in german language:
Loop Antenne aus dem 3D-Drucker
I bought 6 alluminium tubes, 2m long, diameter from 45 down to 20mm for 40m quarter wave vertical antenna. This 10m simple construction collapses to 2m pack with nly 45mm diameter. The base is made from PVC plastic isolator, which is fixed to alluminium plate with 4 M6 screws and additional nut, placed inside the plastic hole, which is normally used to fix the steerer tube on the bicycle.
Photos are worth more than 1000 words…
This is part II for 4 element 6m yagi. Part I is about metal parts. Here is some brief description about electrical connection and preliminary test.
To finish the antenna few parts must be 3D printed (or produced with other materials, like plastic pipes). Holder for air coil consists of three parts: coil holder, coil support and connector holder.
Coil holder is simple cylinder (pdf drawing: chokeholder), which is long enough to accommodate 12 turns of RG58 or similar cable:
Slovenski opis (in Slovenian language)