Pa0nhc 0,03-30MHz active broadband receiving antenna.
For this project you canNOT anymore order the PCBs shown below.
You could use the "dad bug" method to solder both antenna and splitter on pieces blank PCB.
A design for a little, noise- an rattle free power supply, is here.
Splitter and antenna PCBs, ver.20160701.
- New version, using modern BF998 and a BD139 semi conductors
- Real class A circuitry, clean reception without IMD.
- One coax connection.
- Easy soldering :
only one SMD part
grounding connections have thermal relief lines
- Broadband R/C coupling to the receiver, no transformer
With advises for cheap and effective de-noising ferrites
You need a clean, 13.6V / 150mA external power supply, fused at 0.2A.
Parts list including ordering info (PDF)
Construction and installation instructions PDF
MOSfet T1 is soldered on top.
20160915.: If a BDxxx is hard to obtain :
|For your safety, place a 0.2A fuse in series with the +12V connection.
Each antenna performs as good as its installation permits it to.
- For max. sensitivity :
- this antenna should be positioned as high and free from metal conductors as possible
- the ground plane of the PCB must NOT be lower than the top of the mast
(the connection to and the antenna surface itself must be ABOVE the top of the mast).
- For best signal-to-noise ratio :
- install the Miniwhip onto a well grounded mast
- connect "GND" of the Miniwhip PCB to that mast
- place HI-Ui ferrite cores (Ui bwtween 5000 and 10.000) on the beginning and end of all cables to block cable noise currents (see below).
For best noise free reception:
Be sure you are protected by :
TIP : useable and cheap ferrite rings:
Here a few windings through a HI-Ui ferrite core (Ui=5000 to 10,000) block noises coming from the coax cable.
3 times through the hole = 9 times more effective than 1 time straight through the hole.
==>> The ground plane of the PCB should be connected to a noise-free grounded mast at hole h2.
Please read :
Theory about the practice of the Miniwhip antenna (written by pa3FWM).
You can listen to :
The broad band websdr at the university Twente (50kHz to 30MHz).
They use a Miniwhip.