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G8MNY > TECH 19.02.14 14:17l 81 Lines 3171 Bytes #999 (0) @ WW
BID : 56078_GB7CIP
Read: DK3UZ DD3IA GUEST DG6DR
Subj: MW Radio 1st stage
Path: DB0FHN<HB9EAS<DB0LHR<DB0GE<DB0GV<DB0EAM<DB0RES<IK2XDE<IZ3LSV<I0OJJ<
GB7CIP
Sent: 140219/1107Z @:GB7CIP.#32.GBR.EU #:56078 [Caterham Surrey GBR] $:56078_GB
From: G8MNY@GB7CIP.#32.GBR.EU
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 )||
EMW Radio 1st stage
nance 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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