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MTRX-20 (c) RX3G Oleg

te ex vintage radio feritte coils

L1 / L2 seems to be perfect

01/2020 offener Aufbau

01/2020 das Innere

03/2021 neuer Aufbau

Amateurfunk - HAM info » *** QRP ***

MTRX-20 QRP-X (70-250mW) CW Tranceiver nach RX3G

TNX Oleg RX3G for allowing me to assemble your MTRX-20.

Inspired from Oleg I looked his 80-250mW MTRX-20.
The decision was suddently done - fact I want to build one.

First steps are done:
Items which I not have ordered (IC, Transistor, Choke, Ferrite)

Additional ideas:
NE602: - Power supplied with a 78L06 for stable volatage
Keying - with a MOSFET

Today from an vintage mini radio the (mini) Ferrite coils unmounted. Them on a piece copper strip PCB mounted.
L2 = removed some turns from the original coil (maybe from 10 MHz IF). 
With the turnable ferrite fine adjusting 14 000-14 200 possible. Z is infinitly high.
C1 = 55pF. 
L1 = 3 turns
L2 = ? (the coil exists, I only removed turns)

01/2020 in EA8 - see pictures
Now it tooks a bit time for find my desicion how to build up.
Finally I choosed an angle, the bottom with the parts, the uppward part for the plugs, switch, vari C etc.
The Quartz IC Transistor and the Preselection made for pluging.
Some values has changed (I had eg no 1uF C ...- hope 22uF is not too much).
Parts are lot from old PCB's, but I checked all Parts for their function and Value.
Now time for the wires and then checking the copper stripes - and finally will it run ?

Parts list - MTRX-20     C1 62p (Resonance L2-C1 on 14060) C3 150p   C4,15 39p   C8,16 1u   C6,13,14,17,18 0.1u   C11 22u   C7 100u   C5 0-50p   C12 18p / 1000p 75mW / 260mW T1 2N3866   R3 1k Poti   R1 1.5k   R2 10k   XTAL 14060   U1 NE602   U2 LM386   L1 - L1 – see C1   RFC1 - 0.1 0.1u   RFC2 - 56m 56m   Reg1 - 12V 12V   Reg2 - 6V 6V   Switch 1xUM   LSP Audio Plug   Key Audio Plug  

03/2021 QTH EA8
I decided to build up a new MTRX-20.
Now I already had success in receiving Amateurs on 14060 +/-.
Germany, Russian, Slovenia, France I heard.
I see the Quartz is able to pull abt 4 kHz.
But with first coil I had much BCI stations from Marocco...
Now make a new entry coil...


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