Login: GUEST @ JH4XSY.14.JNET1.JPN.AS [Tsuchiura]
home | newest check | boards | help index | log | ps | userlogin | send sysop | slog | status forward | bcm news | users | version | remove cookieG8MNY > TECH 23.06.25 16:04l 87 Lines 3385 Bytes #2 (0) @ WW BID : 35299_GB7CIP Read: GUEST Subj: MW Radio 1st stage Path: JH4XSY<IW0QNL<HB9ON<DK0WUE<PI8ZTM<CX2SA<ED1ZAC<GB7CIP Sent: 250623/0657Z @:GB7CIP.#32.GBR.EURO #:35299 [Caterham Surrey GBR] From: G8MNY@GB7CIP.#32.GBR.EURO To : TECH@WW Here are 2 designs:- By G8MNY (New Graphics Dec 03) (8 Bit ASCII graphics use code page 437 or 850, Terminal Font) Example of multiple use of a single transistor in a MW radio that does:- 1/ RF PREAMP WITH Q MULTIPLIER 2/ RF LOCAL OSC 3/ RF MIXER Power ÄÄÄÂÄÄÄÂÄÄÄ¿ === ³ )|| ______ Decoupling³ === )||( 455kHz ÄÁÄ ³ )||( IF output to next IF stage ³ )||(______ ÃÄÄÄÙ IF T1 ³ TRANSFORMER ÀÄÄÄÄÄÄÄÄÄÄÄÄÄ¿ || )|| F || )|| OSC COIL E || Feedback )|| R || ÚÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÙ || I ||( RF Q Multiplying || T ||( feedback coil || E || ÀÄÄÄÄÄÄÄÄÄÄÂÄÄÄÄÄ¿ || || bias ³ || R || R ³/ || O || ÚÄÄÄÂÄÄ´ÃÄÄÁÄÄÄ´ || D ||( ³ ³\e || ||( ³ Tune ÀÄÂÄÄÄ¿ || A ||( === RF Tune ³ )|| E ||( L1 ³ C1 OSC === )|| OSC COIL R ||( ³ C2 ³ )|| L2 I || ÀÄÄÄÁÄÄÄÄÄÄÄÄÄÄÄÄÄÄÁÄÄÄÙ || A || 0.53Ä1.6 MHz 0.9Ä2.1 MHz L || ADJUSTMENTS The position of winding L1 on the ferrite adjusts the LF resonance tracking. The trimmer on C1 tuning cap adjusts the HF resonance tracking. The position of feedback winding, adjusts RF Q & gain before instability. The position of L1 core adjusts the LF dial frequency tracking. The trimmer on C2 tuning cap adjusts the HF dial frequency tracking. The position of T1 core adjusts the IF filter frequency, for best IF gain. ---------------------------------------------------------------------------- From: ON4CBL@ON0AR.#RF.AN.BEL.EU Hello OM, here is a plan with 1 Tr rf det. + lf,, 2 Tr following for LS! : MW Radio 1st stage reaktieve: 1/ RF PREAMP WITH Q MULTIPLIER + 1x LF LF<----|---> -9volt Stages / / 270 ! /------| 4.7k | (anti-motorB) T1 ! \ _|_ 500pF |-------------|-----/////--------| ! / ___ Cv / 10 | | ! \------| / mH --- - ---- - ! OA81-85 / / --- + 10æF ---- + 100æF ! |-----|----|------| | | F ! | 0.1æ \ / | | ------ E ! --- / | | ---- + R ! --- 680k / | | -- I !A | | | / c | T ! --------------|---| AF116 |----|-----| E ! \ | Over! | \ e | | ! / | | | 1nF / 47k log R ! \ | T2 | --- P /---------- O ! / | | --- / LF out D ! \ | 0.047æ | | | ! ---|----------||-----|--------|----------|---------- ! 0.53-1.6 MHz ----- B --- + - A/B changing for adjusting receiving. T1 40 wdgs cul 0.2 T2 12 wdgs cul 0.2 73 De Eric, ON4CBL @ ON0AR Why don't U send an interesting bul? 73 De John, G8MNY @ GB7CIP
‘O‚̃[ƒ‹ | ŽŸ‚̃[ƒ‹