Pangusar na 21.4MHz Filter ed Walkie-Talkie Field

Pangusar na 21.4MHz Filter ed Walkie-Talkie Field

Say 21.4MHz filter et kaslakan ya uusaren bilang intermediate frequency (IF) filter ed saray walkie-talkie receiver, tan say performance to so direktan mandetermina ed duaran manunan pakapatnagan na walkie-talkies: selectivity tan sensitivity.

Ipaliwawa mi ed aralem manlapud sarayan aspekto:

1. Anto so "Intermediate Frequency" na Walkie-Talkie?

Pian nawalaan na maong ya performance, saray walkie-talkies (tan arum niran superheterodyne receiver) et agdirektan mamapabiskeg tan mamapaabeba ed saray naawat ya signal na radio frequency (RF) (alimbawa, 400-470MHz). Imbes, gagawaen da iray onggendan a kundang:1 Panlalaok: Say naawat ya high-frequency RF signal et ilaok ed signal ya ginawa na lokal ya oscillator.2 Panggawa na Intermediate Frequency: Kayari na panlalaok, walay balon signal ya walay pihon frequency ya nagawa, ya satan so intermediate frequency.3 IF Amplification and Filtering: Say fixed frequency et IF amplified sinala ya malet.

Say bentaha na "superheterodyne" ya istruktura et maslak ed gain tan selectivity (say pakayarin man-filter na adjacent channel interference) et nagamoran na sayan fixed IF section, ya manggagawa ed circuit design ya stable tan ekselentin performance.

2. Akin et 21.4MHz?

Say 21.4MHz et sakey a popular ya standard IF frequency ed VHF/UHF bands (kaiba la ray bands ya uusaren na walkie-talkies). Kaiba ed saray makatantandan rason tan teknikal iran rason to:

Mature industrial chain: Parad 21.4MHz frequency, walay baleg a bilang na mature, stable, tan low-cost ya filter, amplifier, tan arum niran kabiangan ya wala.

Balanse ed baetan na performance tan gastos: Sayan frequency et atagey pian epektibon nasebel so image interference (sakey a kaslakan ya reception interference); diad saman met a panaon, abeba itan pian napagaan so panagdesinyo tan panaggawa na atagey-Q (quality factor) iran filter (singa saray crystal filter tan ceramic filter).

Sayan frequency et inusar ed industriya na komunikasyon ed loob na pigaran dekada, tan dakel a klasikon walkie-talkie chips tan solusyon so adesinyo ed kaliberliber na sayan intermediate frequency.

3. Manunan Betang na 21.4MHz Filter ed Walkie-Talkies

Diad 21.4MHz IF ya seksion, say filter so peteg ya "gatekeeper". Importante so betang to: 1 Paaligwasen so Panpili

Function: Say selectivity et manutukoy ed abilidad na receiver ya ibiig so labay ton signal manlapud dakel ya signal tan i-suppress iray signal ya makaamper ed asingger ya channel.

Panon so kimey to: Say 21.4MHz filter et walaan na maksil a frequency response curve (kaslakan et singa "brick wall"). Abuloyan to labat so signal segment ya walay 21.4MHz ya sentro tan eksakton bandwidth ya ondalan (alimbawa, ±6.25kHz, ±7.5kHz, ±12.5kHz ya kaslakan ya uusaren ed walkie-talkies, ya mipara ed nanduruman distansya na channel).

Praktikal ya epekto: No duaran istasyon na radyo ya asingger so frequency da et manpapasabi ya mankakasakey, say walkie-talkie ya walay high-performance ya 21.4MHz filter et malinew ya makarengel ed tanol na target ya istasyon na radyo, legan ya epektibon nasebel so signal na sananey ya asingger ya channel pian napaliisan so crosstalk. No anggapoy sayan filter odino walay makapuy ya filter, narengel mo so "channel crosstalk" ya ungol.

Paaligwasen so inkasensitibo

Function: Say sensitivity et manutukoy ed abilidad na receiver ya mangawat na makapuy iran signal.

Panon itan ya onkikiwas: Antis ya pabiskegen so IF signal, say filter et usaren pian na-filter so-na-band noise tan interference ya unona. Diad onian paraan, say manunan pamalaknab et say "malinis" ya mausar a signal a mismo. No say amplification et gawaen ya anggapoy filter, say out-na-band noise et napalaknab met, kanian naandi so makapuy ya epektibon signal.

Praktikal ya epekto: Abuloyan toy walkie-talkie mo ya mansiansian natalosan so komunikasyon anggan diad mas arawi odino mas makapuy so signal.

4. Saray klase na 21.4MHz Filter

Diad walkie-talkies, saray kaslakan ya 21.4MHz ya filter et manlalapud sarayan klase:

Ceramic Filter:

Features: Abeba so gastos, melag so sukat, atagey so inkamatoor, tan anggapoy kaukolan ya umanen.

Aplikasyon: Malaknab ya uusaren ed mid-to-low-end walkie-talkies, tan say performance to et magenap pian nasumpal so karaklan ya kaslakan ya pankaukolan. Say bandwidth tan shape factor to (sakey ya indicator pian nasukat so inka-steep na gilig na filter) et kaslakan ya mas mauges nen saray crystal filter balet mas maong nen saray LC filter.

Crystal Filter:

Features: Walaan na atagey a tuloy ya Q value, kanian say selectivity et ekselentin tuloy, tan say shape factor et asingger ed ideal ya estado.

Aplikasyon: Kaslakan ya uusaren ed saray high-end professional walkie-talkies odino diad saray okasyon ya mankaukolan na atagey ya anti-interference capabilities. Mas atagey so bili to nen say ceramic filters.