[Photo] The main points of amateur making parabolic antenna

The main points of making parabolic antennas by amateur--the relationship between the F / D of the parabolic antenna and the radiation direction angle Q of the feed pwtx2.gif (2068 bytes) F / D (F is the focus of the parabola, D is the diameter of the parabola) and the directional angle Q of the feed is a subordinate relationship, which means that the diameter and focal length of the parabolic antenna you want to make can only be determined after the directional angle of the feed is determined . As an amateur, it is not enough to know that F / D = 0.3--0.5. How to make a suitable F / D for an antenna and a feeder is an important issue. It directly affects the efficiency and efficiency of the antenna system. S / N ratio, etc. The Q shown in Figure 1-1 is inherent in the feed. When the feed is determined, Q is also determined.
To make an antenna, we must first determine the feed source. Only when the direction angle of the feed source is known, can we make antennas with different diameters according to different F / Ds. To achieve the desired effect, the situation shown in Figure 1-2 or Figure 1-3 must be produced. The situation in Figure 1-2 will cause clutter reflected from the ground to enter the feed, and microwaves and diffracted waves at the edge of the antenna will also enter the feed, reducing the signal-to-noise ratio of the antenna receiving system. The situation in Figure 1-3 will reduce the utilization of the antenna and cause artificial waste and the side lobes of the signal will also enter the feed. The relationship between F / D and Q is: F / D = 1/4 * Ctg Q / 2.
So first have the feed direction angle and then determine F = D * (1/4 * Ctg Q / 2) according to how many diameter antennas you want to make, and then draw the mold according to the parabolic equation: X = Y * Y / 4F.
The caliber of the parabolic antenna can be calculated by the following formula:
pwtx1.gif (1160 bytes)

Direction angle of feed (Q) 100 degree 120 degrees 160 degrees 180 degree
Antenna efficiency (K) 70% 60% 55% 50%

The direction angle of the general half-wave oscillator feed (with back reflector) and the spiral feed is about 100 degrees.

In-depth analysis of the first-level cache and second-level cache of the technical zone CPU eMMC mass burning dilemma, do you really know? Isolation flyback and non-isolated BUCK application design plan Schottky barrier diode selection and application guide How to use Altium in program design Designer puzzle?

Follow WeChat

Interesting and informative information and technical dry goods

Download Audiophile APP

Create your own personal electronic circle

Follow the audiophile class

Lock the latest course activities and technical live broadcast
Collect People collection
share it:
comment
Publish

related suggestion

[Photo] amateur radio 2m wave 4 unit box wireless

Posted at 2006-04-15 21:11 • 251 views
[Photo] amateur radio 2m wave 4 unit box wireless
[Photo] Collection of amateur FM transmitting circuits (Part 2)

& n ...

Published on 2006-04-15 20:52 • 354 times read
[Photo] Collection of amateur FM transmitting circuits (Part 2)
[Photo] Collection of amateur FM transmitting circuits (Part 1)

This article introduces a few more representative and easy to make in amateur situations ...

Posted at 2006-04-15 20:52 • 618 views
[Photo] Collection of amateur FM transmitting circuits (Part 1)
[Photo] Collection of amateur FM transmitting circuits

Source: Newsletter

Published on 2006-04-15 20:50 • 392 times read
[Photo] Collection of amateur FM transmitting circuits
var check_allow = "/d/Api/iscantalk.html"; var add_url = '/ d / article / write /'; function CheckLogin () {now_uid = ''; var ElecfansApi_checklogin = '/ webapi / passport / checklogin'; var logout_url = "{: U ('Login / logout')}"; var logout_url = 'http://bbs.elecfans.com/member.php?mod=logging&action=logout&refer=front'; $ .get (ElecfansApi_checklogin, function (data, textStatus) {if (data! = "") {EchoLoginInfo (data); CheckEmailInfo (data); data = $ .parseJSON (data); now_uid = data.uid; / * var login_content = 'write an article
'+ data.username +'
Quit '; * / var login_content =' write an article
'+ data.username +'
Set exit '; $ (' # login_area '). Html (login_content); var win_width = $ (window) .width (); if (win_width> 1000) {$ ("# mine"). MouseDelay (200) .hover (function () {$ ("# mymenu"). show ();}, function () {$ ("# mymenu"). hide ();});}} else {var content = 'Login Registration'; $ ('# login_area'). html (content); $ (". special-login"). click (function (e) {$ .tActivityLogin (); return false;});}});} $ (function () {// comment ------------------------------- var comment = $ ("# comment"); var comment_input = $ ("# comContent"); // Submit comment click event interaction $ ("# comSubmit2"). on ('click', function () {var content = comment_input.text (); // Empty input box comment_input. html (""). focus (); // Submit data to server $ .ajax ({url: '/plus/arcComment.php', data: {aid: $ ("# webID"). val (), dopost : 'apiPubComment', content: content}, type: 'post', dataType: 'json', success: function (data) {// Data format returned: if (data.status == "successed") {// Build temporary comment DOM var dom = ''; dom + = '
'; dom + =' '; dom + ='
'; dom + ='

'+ data.data.username +' '; dom + ='

'; dom + =' '+ content +' '; dom + =' '; dom + =' just now '; dom + =' '; dom + =' '; // insert a temporary comment to the list $ ("# comment ") .append (dom);} if (data.status ==" failed ") {// alert (data.msg); layer.msg (data.msg);}}}); return false;}); (function () {/ * * Insert single sign-on JS * / var setHost = 'https://passport.elecfans.com'; // Set domain name var script = document.createElement ('script'); script.type = 'text / javascript'; script.src = setHost + '/public/pc/js/t.passport.js'; script.setAttribute ("id", "sso_script"); script.setAttribute ("data-ssoSite", setHost); script.setAttribute ("data-ssoReferer", encodeURIComponent (location.href)); script.setAttribute ("data-ssoSiteid", "11"); var body = document.getElementsByTagName ("body"). item ( 0); body.appendChild (script);}) () / * * It is recommended to modify the style of the article without a picture * * / $ (". Article .thumb"). Each (function () {if ($ (this). find ('img'). attr ('src') == "") {$ (this) .find ('img'). remove (); $ (this) .parent (). css ('padding-left ',' 0px ');}}); / * Baidu share * / window._bd_share_config = {common: {bdText: '', // Custom share content bdDesc: '', // Custom share summary bdUrl: window.location.href, // Custom share URL address bdPic: ''} , share: [{"bdSize": 60, "bdCustomStyle": true}]} with (document) 0 [(getElementsByTagName ('head') [0] || body) .appendChild (createElement ('script')). src = 'http://bdimg.share.baidu.com/static/api/js/share.js?cdnversion=' + ~ (-new Date () / 36e5)]; var add_url = '/ d / article / write / '; // var check_allow = "{: U (' Api / iscantalk ')}"; var check_allow = "/ d / api / iscantalk"; var click_items_length = $ ('. art_click_count '). length; if ( click_items_length> 0) {var id_str = ''; $ ('. art_click_count'). each (function () {id_str + = $ (this) .attr ('data-id') + ',';}) // var url = "{: U ('Api / getclickbyids')}"; var url = "/ d / api / getclickbyids"; var id_data = 'id_str =' + id_str; $ .ajax ({url: url, data: id_data, type: 'post', dataType: 'json', success: function (re) {if (re.list.length> = 1) {var list = re.list; for (var i in list) {var t emp_id = list [i] ['id']; var temp_span = $ (". art_click_count [data-id =" + temp_id + "]") temp_span.html (list [i] ['click']);}} }})} $ ("# comContent"). click (function () {if (now_uid == '') {$ .tActivityLogin (); return false;}}) $ (function () {var follow_wrap = $ ( ".author-collect"); var now_uid = "{$ _super ['uid']}"; var face_src = "{$ _super ['uface']}"; var getFollowNum = $ (". followNum strong"). html (); // Follow $ (window) .on ('click', '.author-collect', function () {if (now_uid == '') {$ .tActivityLogin (); return false;} if ( $ (this) .attr ('id') == 'follow') {$ .post ('/ d / user / follow', {tuid: article_user_id}, function (data) {// Data format returned: if (data.status == "successed") {$ (". followNum strong"). html (++ getFollowNum); follow_wrap.html ('followed'). attr ('id', 'cancelFollow'). css ( 'background', '# 999'); var follow_user = ' '; $ (' # follow_list '). append (follow_user);} if (data.status == "failed") {alert (data.msg);}});} else {// Unfollow if ($ ( this) .attr ('id') == 'cancelFollow') {$ .post ('/ d / user / cancelFollow', {tuid: article_user_id}, function (data) {// Data format returned: if (data .status == "successed") {follow_wrap.html ('Follow'). attr ('id', 'follow'). css ('background', '# f90'); $ (". followNum strong"). html (-getFollowNum); $ ('# follow_list .face'). each (function () {var target_uid = $ (this) .attr ('data-uid'); if (target_uid == now_uid) {$ ( this) .remove ();}})} if (data.status == "failed") {alert (data.msg);}}); return false;}}});});}); / * var myface = "{$ _super ['uid'] | avatar}"; var myname = "{$ _super ['username']}"; var article_id = {$ article ['id']}; var article_user_id = {$ article ['mid']}; // Article author ID $ (function () {<notempty name = "clearnum"> // Reduce the number of reminders var count = parseInt ($ ("# noticeCount"). html ()); count = count-{$ clearnum}; $ ("# noticeCount"). html (count); if ( count

Lock Motor product introduction:

Safe Lock Motor, also known as The anti-theft lock motor,  in the field of electronic Lock technology, Safe Lock Motor is a mechanical Lock components associated with the electronic control unit of the important parts.


Safe Lock Motor the product effectively combines the advantages of traditional electronic locks and electromagnetic lock overcame the electric lock too much noise, electromagnetic lock power shortage and the development of new products, and spiritual compared with electric control lock and magnetic locks, lock its performance more perfect, more obvious advantages.


Functions: it is widely used in various intelligent locks, such as Shared bicycle lock, fingerprint lock, glass lock, safe lock, hotel lock, family lock, inductive smart lock, etc


Features: Motor For Safe Lock is based on micro precision reducer development, small intelligent micro precision reducer can do 10 mm in diameter, is widely used in safe, locks, smart locks, sensor intelligent lock;

This kind of motor has the characteristics of low noise, low energy consumption, small volume, light quality, high precision, large torque and durability

Method of use: the best stable in horizontal plane, installed on the Safe Lock Motor output shaft parts, cannot use a hammer to knock, knock prone to press into the dc Safe Lock Motor drive, may cause damage to internal components, and cannot be used in the case of blocked.

Lock motor

Operating temperature range:

Gear Motor For Safe Lock should be used at a temperature of -10~60℃.

The figures stated in the catalog specifications are based on use at  ordinary room temperature catalog specifications re based on use at ordinary room temperature  (approximately20~25℃.

If a  Safe Lock Motor is used outside the prescribed temperature range,the grease on the gearhead area will become unable to function normally and the motor will become unable to start.Depending on the temperature conditions ,it may be possible to deal with them by changing the grease of the motor's parts.Please feel free to consult with us about this.


Storage temperature range:

Gear Motor For Safe Lock should be stored ta a temperature of -15~65℃.

In case of storage outside this range,the grease on the gearhead area will become unable to function normally and the motor will become unable to start.


Service life:

The longevity of Dc Motor For Safe Lock is greatly affected by the load conditions , the mode of operation,the environment of use ,etc.Therefore,it is necessary to check the conditions under which the product will actually be used .The following conditions will have a negative effect on longevity.Please consult with us should any of them apply.



●Use with a load that exceeds the rated torque

●Frequent starting

●Momentary reversals of turning direction

●Impact loads

●Long-term continuous operation

●Forced turning using the output shaft

●Use in which the permitted overhang load or the permitted thrust load is exceeded

●A pulse drive ,e.g.,a short break,counter electromotive force,PWM control

●Use of a voltage that is nonstandard as regards the rated voltage

●Use outside the prescribed temperature or relative-humidity range,or in a special environment.

●Please consult with us about these or any other conditions of use that may apply,so that we can be sure that you select the most appropriate model.


when it come to volume production,we're a major player as well .each month,we rurn out  600000 units,all of which are compliant with the rohs directive.Have any questions or special needed, please contact us, we have the engineer group and best sales department to service to you

Looking forward to your inquiry. Welcome to our factory.

Lock motor

Safe Lock Motor

Safe Lock Motor,Motor For Safe Lock,Dc Motor For Safe Lock,Gear Motor For Safe Lock

Shenzhen Shunchang Motor Co., LTD. , https://www.scgearmotor.com