Schematic - last picture! Without any manual. SMD parts capasitors, resistors, inductor. Take note, international shipping is more complicated and longer than domestic, that's why when you buy internationally it mean you are agree to wait for the package.
For Economy International Delivery default stated time is weeks. Some countries may take longer because of your country custom regulation rules or postal service.
PA0RDT Mini Whip – Installing In an Apartment building
All other countries weeks default delivery time. We are not accept any claims for shipping time! Economy Shipping mean we'll send your items with Air Mail, but we cannot promise it will be fast, because it depends on post service, flights schedules, weather accidents, custom processing and other things that out of our control.
Usually it takes weeks. Acabamento e performance excelentes. Wi-Fi control console for hamradio antena switch 8 positions without box. Antenna KIT without power feed unit Schematic - last picture! Power feed unit last picture Power supply V mA or more.
We use only high quality and new packaging materials. Please read carefully product title, description and include list. Any questions are welcome. If you received broken or defective parts please contact us first, because we can resolve this problem in best way. This does not include the number of business days the shipping service will take to deliver the item to you.
We can upload a tracking number during handing time even before your package was transferred to logistic company for the delivery. Works well Works good for small space.Please Note: that all information including pictures on this web page are copyright to Mini-Kits and must not be used on any other web site, or reproduced in any publication.
It is particularly useful for those that have antenna restrictions or limited space to install a full size receive only antenna, and can be used in antenna arrays for noise cancellation or beam forming. The design incorporates static and lightning protection, and has a broadband 50ohm output 75ohm optional output impedance suitable for driving most receivers.
A J FET is used as the active device, and along with a complementary push pull output buffer producing high output second and third order figures reducing the possibility of inter modulation on the received signals.
The design incorporates power supply decoupling so that power can be fed to the Active circuit via the coaxial cable. The recommended Antenna is a 1. The Antenna is physically short for the low frequency HF bands, and will appear as a small 22pF capacitor to ground on the active input circuit. Antennas longer than around 1.
The active circuit and whip antenna is mounted onto a 2 metre long 1 inch The active circuit can then be easily mounted onto the same tube, and then short connection wires are connected from the antenna to the active circuit.
At least 3 ground radials 3 metres long each are laid along the ground for the best performance. Testing indicated that receive signals below 10MHz may require an 10dB gain amplifier on the receiver input to increase signals to a more comfortable level due to the short antenna length.
Some modern receivers incorporate preamplifiers that can simply be switched on, on the lower bands. In very strong AM broadcast areas, some lower quality receivers without good filtering may suffer from inter modulation from strong signal overload.
A suitable 1. The images below show both sides of the board. The construction is quite easy due to the use of larger SMD components and only one transformer that needs to the wound. Click the pictures for a more detaild view. This refers to using the AP90 Antenna which is no longer available from Aeropro. The pole is driven into the ground by around 50cm leaving a length of 1.
Two 3mm holes are carefully drilled through the aluminium tube at a spacing of mm between the holes. The holes on one side of the tube are then drilled out using larger drill bits, and finally a Some filing may be required to fit the insulators through the holes. The bottom insulator has a wing nut and threaded bolt that needs to be removed, as inside the insulator is a spring that is not required so has to be removed so that it does not short the antenna to the aluminium mounting pole.
Next fit the top insulator onto the pole using the standard screw supplied.The antenna is often described as an E-field Probe Antenna as the high impedance front end amplifier measures the potential difference between the antenna plate E antenna and the grounded mast or coax screen. The active antenna designed by PA0RDT may offer a practical technique for exploring radio frequencies below kHz and is reported to offer good performance in the lower frequency bands from 10kHz to at least 10MHz.
Slightly modified from the original design to take advantage of available components this active antenna is intended to trial this type of receiving system. The MPF has similar characteristics to the J transistor with the advantage of the later being low noise however with general higher noise levels of the lower frequencies this should not be a problem.
The circuit is assembled on single sided PCB with the copper clad board separated down the middle. The left side forms the antenna and the right side is ground and has a section of Vero-board glued to the back for component connections. The final board is mounted in a section of PVC water pipe for weather protection.
The board is connected via a very short section of coax to a male N type connector that is fixed to the base of the water pipe bottom end cap. Constructing antennas around the male N type connector allows for mounting on the standard station Generic Antenna Mount. Photo 1 The compact active wide-band receiving antenna circuit board assembled viewed from the front.
Details of the assembly of the board and male N type connector with the water pipe bottom end cap is shown below including the aluminium mounting disc for the N type connector attachment. Photo 4 The active antenna circuit board attracted via sort length of coax to the N type connector within the protective weather cover bottom cap.
Photo 5 The active antenna circuit board attracted via sort length of coax to the N type connector within the protective weather c over bottom cap. Bottom view. Photo 6 The active antenna completed assembly. Installation :. The original mini-whip article by Roelof Bakker, PA0RDT states that the active antenna should be installed on an insulated mast, however there is evidence that the active antenna in fact uses the outside of the coax shield as a ground path there by making the coax shield an integral part of the antenna.
With the coax cable entering the radio room it is highly likely that the system will pick up all sorts of noise from equipment such as computers etcetera; therefore in this installation it is intended that the mast will be conductive and electrically connected to ground to encourage a cleaner system.
Despite attempts at choking the coax cable with a balun, it yelled no detectable improvement as the antenna is of a very high impedance including the way that the coax shield acts as part of the antenna and there appears no way to isolate the coax shield from being part of the antenna by way of choking.
Fig 4 Active antenna installation details. Key installation hardware other than the active antenna are shown below with links to detail pages.
Photo 7 The active antenna installed on stubby mast with out the R. Photo 8 The active antenna installed generic antenna mount details. Photo 9 The masthead coaxial cable power feed unit install in the shack with the computer soundcard interface unit and the TS transceiver. While this is a bit of a rough comparison it is very encouraging.RA0SMS Mini Whip Active Antenna 10KHz 30 MHz Recent acquisition and modifications PA0RDT HD
Comparison set up:. Radio: TSS.
Mini-Whip Active Antenna Module | VLF HF Antenna for SDR Radio | PA0RDT SWL Antenna
Active Antenna in this comparison has demonstrated consistently very good results when compared to the Antenna 1 results. While this appears to be good a results for the active antenna the setup of both antennas is less than optimal, however it is encouraging. For powering the compact active wide-band receiving antenna via the coax cable.
See Masthead coax power feed unit. Details of the generic antenna mount. See: Generic Antenna Mount. Australian aviation non-directional beacon Frequencies. See: NDB Freq. Compare the compact active antenna with the main station antenna.
Reference articles:. Photo 2 The active antenna weather cover mounting plate with the N type connector attached. Top view.The kit contents: extensive documentation, a professional circuit board, and all necessary components. The kit comes with a high quality circuit board, all the parts, a circuit description, building instructions and some tips to combine this antenna with an SDR dongle normally used for DVB reception on a PC or laptop.
The required phantom power supply is not included, but the documentation includes a circuit description of this very simple thing. The circuit of the active antenna. It takes a while to solder the connector, the circuit board has no problem with this, so just heat the pad and connector pin until the solder flows nicely.
Adrian found a cup with lid, which seemed to be the perfect case. I drilled a hole in the lid to hold the BNC connector. I put the lid onto the cup, finishing the antenna.
I put the antenna in the field and compared it with my available antennas. Due to very nearby broadcasting stations on the medium wave band, serious intermodulation occurs, resulting in stations being heard on several frequencies.
Still, it is a very interesting antenna and I think Adrian will really enjoy this thing. Your email address will not be published. I use this lead bending tool for almost all axial components, like resistors and diodes. This way they fit easily in the holes of the circuit board.
The first resistors are in place and perfectly aligned thanks to the bending tool. Using plyers I carefully pull the wires aside a bit, this will keep the components in place. The wires are too long, so I cut them before soldering. You may do this after the soldering as well.
Now the resistors are soldered. All resistors are on the circuit board, nicely aligned and soldered. The capacitors have short wires, so it might be a bit difficult the first time you have to hold the capacitor, put the soldering iron at the right position touching both the pad and the wire of the capacitor and add the right amount of solder.
Start with one pad and a small amount of solder, just to hold it. Now the capacitor is fixed and you can solder the second wire.This article has been copied by request from my VK1OD.
The article may contain links to articles on that site and which are no longer available. For the purposes of this article, the integral amplifier is considered part of the antenna system. The longer the whip, the greater the aggregate signal voltage and the risk of degradation by IMD. The tenor of PA0RDT's articles is that antennas can be made sensitive to only or mainly electric field or magnetic field, and that noise is mainly magnetic field and that an E-field probe will select desired signals whilst rejecting noise.
The theme of E-field and H-field antennas and benefits is a recurring one in ham radio. Because a radiated wave contains E field and H field in fixed proportions, most of the discussion is bunk. Readers will be aware that proponents of the so-called 'magnetic loops' claim that noise is mainly electric field and loops do not respond to electric fields, exactly the opposite to PA0RDT's proposition.
They cannot both be correct, but they can both be wrong! It is true that in the near field, the ratio of E to H is not fixed as it is in the far radiation field due to the induction fields close to the antenna.
It is not only not fixed, but the ratio varies with distance, sometimes the ratio is lower, sometimes higher Anecdotes abound but there is a dearth of measurement support for the claims.
KIT POWERINSERT FOR ACTIVE ANTENNAS WITH BNC CONNECTOR
To analyse this thing, we MUST consider the outer surface of the coax feed line, to ignore it is to analyse something else. We can expect that the electric field close to and parallel with a short good conductor will approach zero. The question then is what is the voltage impressed upon the feed point or amplifier input for a given incident EM wave. This is the classic analysis of a short dipole. But, that is not the case, the lower element is an arbitrary length of coax eventually connected to a ground electrode in PA0RDT's article.
The coax is long enough that assuming a current distribution is unsafe. This notion of capacitance coupling to the E-field also gives rise to the commonly stated need to place the antenna outside the E-field "shadow" of buildings and other structures. PA0RDT said:.
Common advice is to position this antenna above ALL other antennas nearby, which often means a tall support structure which becomes even more relevant the an explanation of how the thing works. However, NEC-4 solves that problem, it handles the segments sizes needed for this article. The last sentence of the quote doesn't make sense, but that is not unusual from antenna designers when modelling tools do not support their propositions.
This model is a little simpler in using a purely vertical feed line, and a common mode choke at the bottom of the feed line ie above the earth electrode. Several people advised that the use of a common mode choke in this position reduced noise substantially, lots of discussions on the net describe some form of "isolating transformer" to fix noise problems. A NEC-4 model was built of a The inset shows the current in the feed point node and the RMS voltage developed across the feed point.
The voltage developed across the input to the amplifier is 6Vrms in round numbers, or 8. But the key thing is that when you look at the current distribution due to the incident wave, this is almost identical to an ordinary monopole, save the small distortion near the top feed point.Antenna KIT without power feed unitSchematic - last picture!
Without any manual. Power feed unit last picture Power supply V mA or more Packaging: The product dispatched carefully packed. We use only high quality and new packaging materials. Please read carefully product title, description and include list. Any questions are welcome. If you received broken or defective parts please contact us first, because we can resolve this problem in best way.
Handling time: 3 business days to process international orders required after receiving cleared payment. This does not include the number of business days the shipping service will take to deliver the item to you. We can upload a tracking number during handing time even before your package was transferred to logistic company for the delivery. Shipping: We dispatch your order during business day.
Take note, international shipping is more complicated and longer than domestic, that's why when you buy internationally it mean you are agree to wait for the package. For Economy International Delivery default stated time is weeks. Some countries may take longer because of your country custom regulation rules or postal service. All other countries weeks default delivery time. We are not accept any claims for shipping time! Economy Shipping mean we'll send your items with Air Mail, but we cannot promise it will be fast, because it depends on post service, flights schedules, weather accidents, custom processing and other things that out of our control.
But Delivery time parcels can be increased up to weeks. Super high amount of views. Top-Rated Seller! Ships on time with tracking, 0 problems with past sales. Like us on Facebook. See Details on eBay Search Swurl. Recent Feedback. See Details.The Mini-whip is an active antenna for the VLF and shortwave bands, the power supply could be fed through the coax with a BiasTee board.
It is a small antenna, it is very suitable for those who is difficult to have an half-wave dipole antenna for LF and HF bands, limited by space of your garden.
You will need to install it up high and preferably away from the house as Mini-Whips are quite susceptible to local noise pickup. Another very important point is that Mini-Whips need to have a good ground connection.
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Lanie Edwin — Only logged in customers who have purchased this product may leave a review. Description Additional information Reviews 1 Description The Mini-whip is an active antenna for the VLF and shortwave bands, the power supply could be fed through the coax with a BiasTee board. Grounding is important: if the antenna is only grounded in the shack, via the coax cable, much noise can be picked up. The strength of the received signal is directly proportional to the height of the antenna above ground, as long as this is small w.
Whether the mast is conductive or not hardly matters for the reception. The antenna is omni-directional, except for a dip straight up. The orientation or shape of the metal plate do not matter; b. Rated 5.