홈페이지> 블로그> Method of making a television antenna amplifier

Method of making a television antenna amplifier

April 12, 2023

Here is an amplifier suitable for indoor TV antennas. It has a simple circuit but works well.

Circuit principle

The circuit of the indoor TV is shown in Figure 1. It consists of only one UHF triode.

The amplifier is powered by G1 and G2 dual power supplies. The circuit features are: for high frequency AC, this circuit is a common emitter ground circuit, but for the DC channel it is a common base circuit. Therefore, this amplifier has a high voltage gain, but the noise is small. Because the power supply is divided into two groups, the b and e junctions of the triode and the b and c junction currents do not affect each other. Therefore, the input and output of the circuit have good isolation, which effectively improves the operating frequency of the circuit and ensures Sufficient bandwidth, with a single-stage amplifier gain of up to 8 dB. If the receiving point is far from the TV station, a two-stage amplifier can be assembled with a gain of more than 15 dB. Because of the better isolation between the stages, when the two-stage amplification is assembled, there will be no serious mismatch or self-excitation. The amplifier's input and output feeders all use a 75Ω coaxial cable, so it fits well with the TV antenna and the port of the TV.

2. Component selection and production

VT adopts silicon NPN ultra-high frequency triodes such as 3DG141, 3DG30C, 3DG30D, 3DG80, 2G911, etc., requiring fT≥600 MHz, β≥100. In addition to the three lead legs c, b, and e, the third type of lead tube has a fourth lead pin, that is, a shell grounding wire, and the lead pin should be grounded during installation. The resistors are all RTX-1/8 w type carbon film resistors, and the capacitors are all CC1 type UHF ceramic capacitors. Inductors L1 and L2 need to be self-made, and they are wound around a 3.5 mm drill bit with a φ0.51mm enameled wire. The power supplies G1 and G2 are both made of two batteries of No. 5 battery.

Figure 2 is a printed circuit board diagram of the machine. The printed circuit board measures 55 x 25 mm. Printed boards should be made of epoxy-coated copper plates with low dielectric loss and high-ground grounding. When installing, the lead wires of each component should be cut as short as possible. The cap of the triode should be embedded in the circular hole of the printed circuit board, and the four lead legs are welded to the opposite side in a blue-like shape. The circumference of the printed board should be surrounded by copper or tinplate with a height of about 15 mm. It should be soldered firmly, capped up and down, sealed into a metal box (see Figure 3) to prevent interference from external clutter signals. The input and output lines are taken out of the box with a 75Ω coaxial cable. Then pull out the plastic power cord from the small hole on the side, and connect it to the power supply to work reliably.

Figure 2 TV printed circuit board

0 times
Window._bd_share_config = { "common": { "bdSnsKey": {}, "bdText": "", "bdMini": "2", "bdMiniList": false, "bdPic": "", "bdStyle": " 0", "bdSize": "24" }, "share": {}, "image": { "viewList": ["qzone", "tsina", "tqq", "renren", "weixin"], "viewText": "Share to:", "viewSize": "16" }, "selectShare": { "bdContainerClass": null, "bdSelectMiniList": ["qzone", "tsina", "tqq", "renren" , "weixin"] } }; with (document) 0[(getElementsByTagName('head')[0] || body).appendChild(createElement('script')).src = 'http://bdimg.share. Baidu.com/static/api/js/share.js?v=89860593.js?cdnversion=' + ~(-new Date() / 36e5)];
문의하기

Author:

Ms. Zoe Zhong

Phone/WhatsApp:

+8618617178558

인기 상품
You may also like
Related Categories

이 업체에게 이메일로 보내기

제목:
이메일:
메시지:

Your message must be betwwen 20-8000 characters

2010 년에 설립 된 Entnorson Antenna Co., Ltd는 커뮤니케이션 안테나의 연구, 개발, 판매 및 서비스에 종사하는 전문 회사입니다. Yetnorson은 2 g/3 g/4 g/wifi/TV 안테나와 다양한 RF 커넥터 및 안테나 케이블 어셈블리를 전문으로했습니다. 우리는 5 명의 엔지니어가있는 R & D 팀이 7 일 이내에 고객의 사양에 따라 프로젝트를 완료 할 수 있으며 귀하의 옵션을 위해 500 가지 이상의 현재 안테나 제품을 제공합니다. 그 동안 36 개의 제품 특허와 8 개의 상표가 있으며 ISO...
Newsletter
회사 주소
Room #101,201,301,5BLDG , No.4 of XinWuCun New Area ,Shabo community Maluan Street Pingshan District, Shenzhen ,Guangdong , China, Shenzhen, Guangdong China

Copyright © 2024 Yetnorson Antenna Co., Ltd.판권소유

Copyright © 2024 Yetnorson Antenna Co., Ltd.판권소유

We will contact you immediately

Fill in more information so that we can get in touch with you faster

Privacy statement: Your privacy is very important to Us. Our company promises not to disclose your personal information to any external company with out your explicit permission.

송신