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G8MNY > TECH 25.04.24 03:02z 87 Lines 3385 Bytes #29 (0) @ WW
BID : 5713_GB7CIP
Subj: MW Radio 1st stage
Path: SR8BBS<SR4BBX<SR1BSZ<IW0QNL<JH4XSY<N3HYM<VE3CGR<KA1VSC<GB7CIP
Sent: 240418/0923Z @:GB7CIP.#32.GBR.EURO #:5713 [Caterham Surrey GBR] $:5713_GB
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
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