PA0RDT Mini-whip active receiving antenna is finished product, you need install 18650 battery and ground net , then it will work,
Note:
we will not send to you the 18650 battery, because air forbid
This antenna is only suitable for outdoor use, it can only listen to FM radio when in indoors
?
This new version of PA0RDT MiniWhip Antenna has these features
- New version, using modernMMBFJ310 and 2SC2570 semi conductors
- Real class A circuitry, clean reception without IMD.
-One coax connection.
- Broadband L/C coupling to the receiver, no transformerTechnical
Specifications:
Frequency range: 10 KHz - 150 MHz
Power: 12 - 18 volts at 50-75 mA
Secondorder output intercept point: > + 70 dBm
Third order output intercept point: > + 30 dBm
Maximum output power: in excess of - 15 dBm
PCB Size: Length (mm): 90x 30
Connector: BNC or M or N
Feed line: 50 - 100 ohm coaxial cable up to 80 meter long
Each antenna performs as good as its installation permits it to. Any active antenna is not working good inside the house
The MiniWhip
The figure shows a sketch of a typical MiniWhip setup. It consists of a mast of a few meters high, ideally in the open field, with on top of it a small metal plate and an amplifier, together in a plastic enclosure (the actual MiniWhip). A coaxial cable runs from the MiniWhip down along the mast to a receiver. For now we assume the mast is conductive and grounded, but we will later see what happens if this is not the case. The amplifier is a voltage follower with a very high input impedance in order not to load the metal plate, and a low output impedance to be able to deliver sufficient power to the 50 ohm coaxial cable; see [1,2,3]. The idea is that the metal plate "measures" the electrical field at its location, and sends the result via the coax to the receiver.
? Conclusions
What can we conclude from all of this theory?
- The MiniWhip is vertically polarized.
- Grounding is important: if the antenna is only grounded in the shack, via the coax cable, much noise can be picked up. B.t.w., that grounding does not need to be galvanic: a large piece of metal, even if not connected directly to the earth, may have enough capacity to serve as ground.
- The strength of the received signal is directly proportional to the height of the antenna above ground, as long as this is small w.r.t. the wavelength.
- Whether the mast is conductive or not hardly matters for the reception. However, if the mast is conductive, the antenna&39;s plate must of course not be mounted besides but above the mast.
- The antenna is omni-directional, except for a dip straight up.
- The orientation or shape of the metal plate do not matter; b.t.w., this is also true for the whip in case of whip-based active antennas