More than 20 years ago, the circuit of small-scale radio frequency that is produced more than of about 40m is difficult. But vary with time, to the structure of radio frequency for example, overall arrangement, earthing and shielding Understanding get certain development. People find gradually: Can follow certain rule as in low frequency, succeed in producing the circuit of radio frequency out.
About shielding, a problem has been existing and disputing all the time. You may know what an overall arrangement and earthing, but it usually needs a better outer cover to shield. Low priced aluminium outer cover available for amateur electronic fan of great majority on the market, as to direct current and AM being enough kind in broadcast. But will go wrong when the frequency rises to HF and VHF district. As to what a result of receiving the good shielding, you yes He Xin?s view? If you have read the special column article that the author wrote over these years, you should remember the author has ever reminded the person who produce circuit of radio frequency to use the edge to have aluminium outer cover that at least 0.25in overlaps, and should cover very tight. A lot of outer covers available for amateur can not all reach the requirement of this on the market.
The radio frequency of steel that is a series SB-x of SESCOM of Fig. 1 shields the outer cover. Notice it ? fork refer to the intersection of form and the intersection of raised paths between fields and structure, this can make outer cover and cover buckled more urgently. It is to insert the part in it and some to have, for the shielding between every internal part. Hit hole of troughs on the outer cover, inserting one protrudingly can be welded on trough hole in the appropriate position, strong, it is good to shield the result.
A style in Fig. some series 1 SESCOM: Have fine shielding outer cover of radio frequency, it has used ? point the form ? on the cover Structure, make it deducted in the shell closerly
Originally, the author still relatively cares about the material question: The tin-plated iron outer cover should be superior to the aluminium shell. Tin-plated layer is easy to weld, but it is difficult for the iron to hole. The author finds in the experiment, SB-5 outer cover using the high-quality bit to provide for SESCOM does not have any difficulty to hole. Certainly, if use the old bit and slope and use, then you are certain to destroy it. But if the technology of holing and uses the high-quality sharp bit not to have any question skillfully.
There are 11 kinds of size in these outer covers, bottom area, since 2. lin * 1.9in, to 6.4in * 2.7in, in height for 1 of 0.63in, 1.0in ors. lin,compared with the situation that the radio frequency shields the unsatisfactory high-quality aluminium quality outer cover of performance, have very great advantages at the price.
Fig. 2 is that a small-scale AM broadcast the radio frequency preselector. It stands from nearby transmission and receives the faint signal to amplify and reduce the noise. Mediate the electric capacity to install on the front panel, it is usable to contain the knob. Front there are switch buttons at the panel ? There is a battery that wraps up in the aluminium base as direct current source . Inductor that work together with condenser insert, punch board ? Have other parts of circuit on it With the following panel ? Affixed to and regulated on slice During.
The design in Fig. 3 is used for measuring one and handing in and adjusting the receiver directly. The circuit board designs to enable the circuit module, it is easy to replace different parts of the circuit by other designs. Here plant method because of ? The apple is to the apple ? Principle designing.
The radio frequency that battery of Fig. 2 supplies power is designed
The receiver base of Fig. 3 is regarded as ? testboard ? ,Various correction used for measuring general design
This entry was posted on Wednesday, June 1st, 2011 at 5:29 pm and is filed under Uncategorized. You can follow any responses to this entry through the RSS 2.0 feed. You can leave a response, or trackback from your own site.
Source: http://hujk.org/the-radio-frequency-shields-the-outer-cover-principle/
nordstrom tempurpedic natural born citizen 4chan roy oswalt doppler radar michael vick
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