wide band (DX) receiving antenna.
New version. Preliminary development data.
Sets new version PCBs will become available, and will be delivered including
Price and delivering date not known yet.
You need a clean, 12.6V /
150mA external power supply.
This is a vertically polarized
receiving antenna. Perfect for medium range and DX reception.
But (like all vertical antennas) it is NOT suited for NVIS reception (short range communication between 1.7 and 7.2 MHz)..
- New version 13, improved setting of T1, and commonly available new type UHF transistor for T2.
- Real class A circuitry, clean reception without IMD.
- Biggest strong signal handling.
- Maybe not the strongest signals, but the cleanest reception if well installed.
- Really wideband with R/C coupling to the receiver, no transformer, adjustable output impedance for critical cable lengths.
- One coax connection.
- Only commonly available parts.
- Only two SMD components with enlarged solder pads, easy soldering.
- With advises for cheap and effective de-noising ferrites
Klick HERE for the partslist.
Highly recommended to
Theory about the practice of the Miniwhip antenna (written by pa3FWM).
Listen DX at :
The broad band websdr at the university Twente (50kHz to 30MHz).
They use my "Miniwhip".
Updated antenna unit
The antenna surface
"ANT" must be FULLY ABOVE the metal mast.
New splitter circuit.
Use two extra nuts for space between PCB and the bottom of the box.
Every 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 connecting trace between the electronics and the antenna surface, and the antenna surface itself must ALL 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 (h2) to that mast
- place HI-Ui ferrite cores (Ui between 3000 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:
(Earlier version antenna PCB).
Here a few windings through a HI-Ui ferrite core (Ui=5000 to 10,000) will block noises coming from the coax cable.
3 times through the hole = 9 times more effective than 1 time straight through the hole.
Use thin coax with maximal number of turns through the ring core.
==>> At h2, the ground plane of the PCB should be connected to a noise-free grounded mast.