LABORATORY POWER ADJUSTABLE 0 V A 235 In (C.A. E C.C.) 6-2014
LABORATORY POWER ADJUSTABLE 0 V A 235 In (C.A. E C.C.) 6-2014
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6 METERS - 50 MHZ BAND AMPLIFIER FOR CONSTRUCTION OF A MAGIC 300 W CON GI7B 6-2014
6 METERS - 50 MHZ BAND AMPLIFIER FOR CONSTRUCTION OF A MAGIC 300 W CON GI7B 6-2014
6 METERS - 50 MHZ BAND AMPLIFIER FOR CONSTRUCTION OF A MAGIC 300 W CON GI7B 6-2014.pdf
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Pixie ANTENNA (IXI THE PORTABLE ANTENNA) 6-2014
Pixie ANTENNA (IXI THE PORTABLE ANTENNA) 6-2014
Pixie ANTENNA (IXI THE PORTABLE ANTENNA) 6-2014(2).pdf
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I8SKG Giuseppe Ballet

I8SKG Giuseppe Ballet

L’ ANTENNA
(A CHANGE IN INCOME)

After describing the changes to bring our RTX, SHAK-TWO, to operate on the frequency of 50 Mc, accessories (Circuit Calibration of Scale and Noise Limiter Pulse) and the PA for the SSB, I am going to describe a small and undemanding to bring change to work in Banda 50 Mc RINGO of an antenna 27.
antenna balletta1The choice of a Vertical Antenna, in my opinion, is convenient for use in the VHF and, especially for 50 Mc, for those who find themselves surrounded by mountains which prevent beneficial use of a directional antenna (is my case, by Appunti).
On the other parte, for the experts working on 50, it is known that connections are made with the DX Sporadic E and, therefore, also just mediocre antenna when this phenomenon is present. At the end of Sporadic E connections are, as for 144, at optical or near-.
Now we come to our antenna to edit. The operation was carried out on a RINGO of ECO and ANTENNAS, precisely, Article 5 Catalog. The main task is the sawing in half coil arrangement at the base so that, two coils of which it is composed, He una rimanga, without altering the diameter.
The development is carried out as usual: with a lot of patience, equipped with the SWR meter, rule is roughly the height as indicated in the drawing on the next page, to approximately 3,95 m from the coil core. The bridge linking the antenna connector and the coil of the modified base, is connected with its clamp around 2/3 its, side mass.schema balletta1
This way as the initial. The antenna I have distanced approximately 80 cm from the metal railing of my terrace, and in this regard we can refer to the attached drawing for more accurate details.
All indications suggest that it is obvious that they are indicative that, certainly, who has experience on the development and assembly of this type of antennas, will know well how to operate.
The minimum of ROS will obviously acting both on the length of the antenna is about moving the jumper on the reel basic agreement.
antenna balletta2I also suggest not to raise too much of the antenna from the balcony, orienting on 80 because suggested cm, lifting more, you will not earn much on the horizon and you can create some problems on the coil of the basic agreement.
Hoping to have expressed the need, I wish you good work and good DX.

I8SKG, Giuseppe Ballet
Via Nazionale, 176
S. Maria a Vico
81038 Caserta
Such. 0823 808113

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ANTENNA FOR CIRCULAR ELEMENTS 23 CENTIMETRI H.M.

Recitalnicola antenna
In the many years of being in love with the radio and VHF and higher frequencies, I also spent a lot of time to 23 centimeters with
the construction of Yagi antennas and also working on the parables, illuminators of various shapes and so much material of any kind, from metal containers of coffee, the stand and all this to find an antenna designed to replace a parable because most handy and ready for use. Then I saw in a magazine very original antenna that I thought was interesting now, light, di un bell’aspetto, with a building within my reach
and a fraction of the cost compared to the antennas on the market. Also, in casa, I noticed that you have all the material needed for its realization. It takes a little 'time, a little 'patience, a little 'precision and, certainly, in a few hours you can accomplish this original antenna. I must say that compared to the draft that I had seen I made some substantial changes to make it more efficient.

nicola 2circular antenna

Materials required circular antenna 1

- A small sheet of aluminum, thickness 1 mm
- A shaft of square aluminum 12 x 12mm, length of approximately 2 meters
- A strip of copper of a thickness 1 mm
- About 25 inches of coaxial cable abbastanzarigido
- An attack by post, I got to unavecchia Fracarro; you can use a similar
- About 30 brass screws with nut, length 22 mm and a diameter 2,5
- A reduction with N connector
- A lot of patience and precision with respect to the measures, since we are at 1.2-1.3 GHz!
The construction, per me, was very pleasant, fun and fast.
The first thing to do is to pierce the aluminum rod long 2 meters which has become the boom, with a drill and drill adapted to the brass screws that we use. I receive 18 holes must be made at a distance of 9 cm (center-center) the width of the rod, partendo of circa 6 cm from the beginning of the boom (Fig. 1 next page).
The holes made will serve to place the elements of circular shape, the radiating element and the reflector. It takes, then, the aluminum plate and with a shears are made of strips of length circular antenna 2 of 220 mm and the width of regular 4,8 mm. If you do not have a veneer home just go to any blacksmith and is a work of a few minutes.
Once you have made the strips of aluminum must be cleaned, with a lime, from the dross and straight as surely, during the cutting, you are a bit 'distorted.

 

circular antenna 3 schema

On the strips from 220 mm making two holes, with the tip with which has been pierced the boom, as shown in Fig. 2 (above) the distance center to center of 212 mm. Once cleaned the holes with a much larger tip is passed to the circular antenna 3 construction of the elements with the help of something circular (I used a can of soft drink) which is the ideal. Appena curvate, passing the brass screw in the two holes (Fig. 3, side) and tighten with the nut. It repeats this for 22 times and at the end of our work we 22 components ready for assembly on boom.
It then goes to the construction of the radiating element using the strip of copper that must have the measure of 243 mm x circular antenna 44,8 mm (Fig. 4, side).
The holes should be made following
the measures of the drawing
reported remembering
to make a hole even in the middle of the strip of copper

The two side holes circular antenna 5
Radiant dell'elemento
must have a diameter
lower than the tip
used for the elements, while the central hole will
always the screw diameter of brass and serve for fixing it to the boom. The radiating element will be fixed in a manner contrary with respect to the elements already set. Before attaching the element is good solder the wire drive (RG303U ‐ 50 Z) as shown in Fig. 5.
In the hole in the center of the strip of copper is inserted, in the part below the radiating element, also a die that will serve for fastening. Behind the hole already made for the passage of the screw, will be made another hole the diameter of the wire used and, once you pass the wire through the hole, you will lock to the radiating element and the welding of the N connector with reduction.
circular antenna 6Finally we will have to build the rectangular aluminum reflector with the measurements shown in Fig. 6. Once the construction of the reflector, the same is inserted in the boom, they fasten it with two brackets and external work is completed!
Now just make two holes in the spotlight after the application for the attack on the pole.
A very important aspect is the precise alignment of the elements. Being an antenna with the attack circular antenna 7 circular antenna 8
external, the weight could, with time, Lower the antenna and fold
with the tip downwards; in this
For best results, put a rod
Nylon tipped over to the attack
dell'antenna the palo (master). Remember to put two caps
plastic end of the boom.
Actually my antenna, although
mounted from different time, had no mechanical problems of any kind.
Now just try it, standing waves are very low (1.1 ‐ 1.2) if you meet all the suggested measures and the gain very high in relation to its length.
From comparative testing carried out is equivalent to a parable 1 m diameter, it costs very little compared to commercial prices and is built in a short time, in addition to the pride of
you create it by yourself.
I tried the antenna in "circles" from home,
in Contest and DX-pedition with results
surprising; in particular has stayed with me in Spain EA5/I0SNY, in Marocco CN9CR, ZB2/I0SNY a Gibilterra, Ceuta EA - 9/I0SNY ... and in many other activations with many QSOs over the 1000 km with the help ..., certainly, to the good propagation.
Good construction and good DX.
73
I0SNY,Nicola

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Our partner IZ8WLZ, Nino Molinari, Apple developer, and raise it to put online for i-phone app that will allow us to calculate a Moxon directly on our laptop.
intro

main

promoMoxonHere are the links to download the Vs I-phone:

Link diretto iPhone:
https://itunes.apple.com/us/app/imoxon/id828581164?mt=8&uo=4
HTML to insert to bring up the little button "available on AppStore":

<a href=”https://itunes.apple.com/us/app/imoxon/id828581164?mt=8&uo=4″ target=”itunes_store” style=”display:inline-block;overflow:hidden;background:url(https://linkmaker.itunes.apple.com/htmlResources/assets/en_us//images/web/linkmaker/badge_appstore-lrg.png) no-repeat;width:135px;height:40px;@media only screen{background-image:url(https://linkmaker.itunes.apple.com/htmlResources/assets/en_us//images/web/linkmaker/badge_appstore-lrg.svg);}”></a>

Direct Link iPad

The program calculates the size in centimeters and inches by entering the desired frequency and the diameter of the wire or tube used

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HEATHKIT HW-8HEATHKIT HW-8
A legendary QRP CW transceiver that has made history

Fabio Bonucci, IKØIXI

Talking dell'Heathkit HW-8 is not easy. It is a well known apparatus, appreciated by thousands of amateur radio operators around the world since its debut, occurred in the distant 1976. On it were written dozens of articles, developed many modifications, designed and made countless improvements. Anyone who wants can find on the web for anything and everything.
I will then describe the principle of operation, its strengths and its flaws, small changes to make it more suitable for my needs. But the whole thing just under my personal point of view, it is then that of a ham with the fixed dell'autocostruzione and QRP transceiver struggling with a little vintage that you do not want (and you should not) upset but keep as much as possible to its original condition. A necessary act against a fascinating apparatus which is an excellent example of "teaching practice" in the context of amateur radio. The interesting side of an HW-8 is not the technical or performance; the far more important aspect consists in the fact that this has been for all those who have found themselves in a position to build. His book is in fact a real course that the amateur in the process of building it was to deal with step by step if he wanted to come to its realization. In this journey he was taken in hand by the complete installation and setup, supported by very clear illustrations, who brought in a few days to complete its assembly and calibration. Once finished, the HW-8 gave the satisfaction of making a QSO with something that had come out from his hands. It was a very informative way to amateur radio, a formal school for young amateurs. Even today in our world surviving examples of this tradition, but the Heathkit made it a way of life and for many years; sin no longer exists.

Principle of operation
Technically speaking, the HW-8 is a radio transmitting apparatus based on sincrodina. In modern times it is called "direct conversion". In practice, the signal received from the antenna is amplified and mixed with a locally generated signal and having a frequency close to that of the antenna signal. The frequency difference between the two signals falls in the audio band, it is easily filterable and audible via a speaker. For example, if we want to get a CW signal on 14060 kHz, the local signal must be tuned to 14.059.2 kHz oppure a 14060.8 kHz, or 800 Hz below ( or above) the carrier of the signal to be received. In this way you will have an audio signal output of the mixer equal to 800 Hz. The first thing you notice is that during tuning will find two CW identical short distance from each other. This is the first "defect" of the direct conversion. Also, a receiver so made must rely largely of selectivity and sensitivity to the low-frequency (since there is the stage of intermediate frequency, there are no intermediate amplification and filtering). Furthermore, the local signal is directly in the reception band, constituting a potential nuisance to neighboring receiving stations. For the benefit, there is a remarkable structural simplicity compared to traditional superheterodyne, while maintaining acceptable performance.

Details constructswe
HW-8 the antenna signal is pre-selected via a front-end consists of 4 tuned circuits, one for each band (3.5 – 7 – 14 – 21 MHz), selectable by command of band change. The signal is then amplified by an FET that leads to the entrance of the active mixer MC1496, ready to be mixed with the local signal generated "conversion". A VFO exists between 8.645 and 8.895 (250 kHz extension) is mixed by a mixer diode with 4 crystal oscillator of fixed frequency (HFO) depending on the desired band (12.395 kHz for 80m, 15.895 kHz per 40m, 22.895 per i 20m e 29.895 kHz per i 15m). This system allows you to take advantage of the stability and the extension of a VFO 8 MHz to generate signals on the ranges of interest (as mentioned, the local signal in this type of radio must be close to that of reception). The signal thus obtained is higher by a selective amplifier and made available for the active mixer MC1496, and ready for the drive chain. The uscita the MC1496 Mixer, now the low frequency, is filtered and amplified to the speaker-phone. For the transmission things are much simpler; the local signal is amplified to bring it to the desired value, manipulated by the key that, via the keying circuit, also creates an offset of the VFO during transmission. A side dish of all, there are some circuits accessories, as the mute and sidetone. Everything here. 13 transistors, 2 Integrated, various resistors and capacitors; basic but very effective.

Problems
The original design of the HW-8 suffers from some limitations, more than understandable for a simple apparatus, cheap and easy to build even for those who are beginners in the field of radio engineering. Mainly, the HW-8 suffers from serious problems in Intermodulation on low ranges, species on 7 MHz. Often you listen to the broadcast while you are in 40m. The poor selectivity of the input circuits, the low dynamics of the FET used as antenna amplifier, insufficient resistance to strong signals from the mixer MC1496 are the key elements that determine this deleterious effect. The direct conversion is not a system of optimal reception, is only one of the simplest. The only remedy to not upset the apparatus in its interior consists of placing a suitable filter selector and employ external antenna monoband. If instead you want to change the HW-8, it is necessary to reconstruct the input filters and make them very selective though at the expense of frequency coverage (against the other, is incomprehensible to provide an apparatus CW only as much 250 KHz per ogni banda, enough to the maximum 70 KHz..). Then should be used as an antenna amplifier BJT in place of the FET, maybe a great 2N5109 with excellent dynamic behavior. Passing al mixer, it would take a DBM (Double Balanced Mixer) that is not easily intermodula in the presence of strong RF signals. This change would also entail the increase of the signal level conversion depending on the mixer used (minimum + 7 dBm), raising issues relating to the placing of signal range. In transmission instead, power 0.5 - 1.4W can be increased with the inclusion of one stage MOSFET type IRF510. Space on the rear panel there is enough to make any change to the number of end-stage. With all these changes, sure the HW-8 would become an almost comparable to a super-heterodyne transceiver; but she will be out of a system upset, "Raped", to the point that lose all historical value. Personally, despite having made changes even heavier on other devices (vedi NRD-525), I am opposed on principle to upset a vintage apparatus to improve performance. In some devices you should look for the performance but the feelings that can convey to those who use them, the emotions arising from the use of a radio that belongs to our youth, to a lost world of radio that "human", or think on a human scale, that is, they could be built, aligned, repaired in the home by an amateur with some tools but mostly armed with good will and desire to learn. In other words, I do not care what you can do the HW-8 but rather what you can give me in terms of emotional. For this I have to make only limited 3 improvements to non-invasive, harmless and fully reversible, now that I'm going to show you.

S-Meter
Originally the S-Meter HW-8 only works in transmission, providing an indication of the output power, useful for verifying that the equipment sending and the Loading is adjusted for maximum output. But it is nice that it is receiving property, it seems that the receiver is turned off. For this reason I decided to reveal the low-frequency and bring it to the instrument in order to give back in some way a "semblance of normalcy". It's not like reading the AGC voltage, but it is always an interesting indication, however, and gives an idea of ​​the signal you are receiving.
Here is the scheme, simple:

s-meeter

Frequency
The scale of the HW-8 is not bad but, each speaker as small-scale, definition of sin. The extension of 250 kHz does not make things easy and not possible to know exactly which frequency you are tuned. And my eyes are not what they used to be ... This is detrimental to the QRP, in which it is essential to place the call on frequencies reserved to it. Having a digital frequency Norcal FCC-1, I thought I would pick up and read the local signal conversion before it reaches the mixer, in order to be sure of the exact tuning frequency. This signal can be downloaded via a ceramic capacitor from 47nF on foot "hot" resistor R51 (l’altro capo è a massa). With a shielded cable RG-214 you can carry out up to 8 dall'HW-frequency. Taking advantage of a hole in the rear panel by some previous owner, I mounted an RCA jack that I have dedicated to this purpose. Being a programmable frequency, I set the beat frequency 0.8 kHz so as to compensate the frequency difference between the carrier and the beat note. Now on to my HW-8 looks good a little "digital readout", legacy of yore, with which I can easily tune the International QRP frequencies or frequency can always be sure that I'm reading.

FrequencyFrequenzimetro2
Thanks to the frequency they are now free of the scale and I thought to reduce the extension of the VFO half, ovvero a 125 kHz. This trick allows you to "soften" the tune, halving the available bandwidth while maintaining all portions tunable range of the CW. Just add a ceramic capacitor from 28 pF in series with the variable tuning and re-step the VFO through the inductance L19. Now the HW-8 tunes only 125 kHz from the beginning of each band, making the tuning stations decidedly less critical.

Conclusions
With this apparatus I have connected many European stations on 40m and 20m in 2XQRP, while on 15m I was able to hear me with only U.S. stations 500 mW.
What more? I highly recommend buying a device like this. You'll find yourself in front of a simple radio and dated, but still able to give you a feeling of unparalleled fun.

73 de Fabio, IK0IXI

Pixie ANTENNA (IXI THE PORTABLE ANTENNA) 6-2014
Pixie ANTENNA (IXI THE PORTABLE ANTENNA) 6-2014
Pixie ANTENNA (IXI THE PORTABLE ANTENNA) 6-2014(2).pdf
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6 METERS - 50 MHZ BAND AMPLIFIER FOR CONSTRUCTION OF A MAGIC 300 W CON GI7B 6-2014
6 METERS - 50 MHZ BAND AMPLIFIER FOR CONSTRUCTION OF A MAGIC 300 W CON GI7B 6-2014
6 METERS - 50 MHZ BAND AMPLIFIER FOR CONSTRUCTION OF A MAGIC 300 W CON GI7B 6-2014.pdf
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LABORATORY POWER ADJUSTABLE 0 V A 235 In (C.A. E C.C.) 6-2014
LABORATORY POWER ADJUSTABLE 0 V A 235 In (C.A. E C.C.) 6-2014
LABORATORY POWER ADJUSTABLE 0 V A 235 In (AC POWER AND CURRENT) 6-2014.pdf
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