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G8MNY > TECH 29.07.15 14:43l 80 Lines 3657 Bytes #999 (0) @ WW
BID : 37328_GB7CIP
Read: GUEST
Subj: Systron Donner 1702 Sig Gen
Path: IW8PGT<CX2SA<OZ5BBS<ON0AR<VK6HGR<GB7CIP
Sent: 150729/1128Z @:GB7CIP.#32.GBR.EURO #:37328 [Caterham Surrey GBR]
From: G8MNY@GB7CIP.#32.GBR.EURO
To : TECH@WW
By G8MNY (New Jul 13)
(8 Bit ASCII graphics use code page 437 or 850, Terminal Font)
In 1998 I bought this large digital signal generators in & not regretted it. It
is a deep 19" 3U rack unit with side handles, & weighs 25kg!
Mod Frequency Lever Wheels am 0-120dB
____________________________________________________________________
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³ ³ ÚÄÄÄÄÄÄÄÄ¿ ÚÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄ¿ | o ___ (_)³ ³Tune
³ ³ ³ 18.10 ³ ³9 Ý9 Ý9.Ý9 Ý9 Ý9 Ý9 ݳ | / \ /~~\ ³ ³
³ ³ ³________³ ³ Ý Ý Ý Ý Ý Ý Ý³ | ³ /~\ ³ ³ ³ ³ ³Atten
³ ³ ÀÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÙ | ³ \_/ ³ ³ ³ ³ ³1-10dB
³ ³~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~³ \___/ \../ ³ ³& Zo
³ ³ (_) (_) __ __ __ __ ³ ³ ³
³ ³o [Û ] [__] [__][__][__] ³ o (o) o o ³ ³Trip
³ ³' (ú) Äo (ú) ³ ' ³ ³
³ ÀÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÁÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÙ ³
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AF osc mod ext Power FM CW AM On/Off N o/p Reset
It was made in the USA by Thorn EMI that owned the SYSTRON DONNER Co. in 1983
at around $10000!
It uses several PLL oscillators & mixers, all locked to an internal/external
reference. It has a calibrated 4 digit display of peak AM & FM modulation from
the built in locked 400Hz & 1kHz sine wave sources as well as external
modulation.
It was not all working (e.g. no 144MHz), & later a main smoothing cap O/C. But
I have managed to repair all the faults, without a diagram! Which was very time
consuming, working out how it all worked (internal silvered brass sectioned RF
unit & 16 gold plated PCBs).
I have done several mods to it now, eg. FM deviation increased to ñ100KHz,
improved modulation bandwidth > 30KHz, off reference fine tune, & external 625
line TV timebase lock (obsolete now with digital TV!)
MY SPECIFICATION
AC Mains input 240V 40-100Hz @ 50W on rear IEC connector
Mains voltage links on plug inside.. 250, 220, 125 110V
RF Output N socket 50ê. 0.1uV to 1V RMS Max
Attenuator 120dB 20dB/step & 10dB 1dB/Step attenuator (& Term)
Frequency Range 100Hz to 999.9999MHz in 100Hz steps,
using 7 large lever operated thumb wheels
Accuracy 1/10^7 internal temperature compensated Xtal reference
Off Calibration Fine Tuning ñ70 PPM
Frequency accuracy compromised on FM by ñ5Hz jitter!
Rear 1 MHz BNC O/P Reference TTL level
Rear 1 MHz BNC External input Reference TTL level
Harmonics & spuri lower than -30dBc, typical -55dBc. 400MHz mix system
Accidental Tx RF trip relay @ >500mW in, 10dB atten is unprotected!
PLL lock indicator & Level correct indicator (AGC OK eg. not in AM)
Modulation FM Indicated 19.99 or 100.0KHz, AM 0.0-100.0% (clips @ 95%)
Internal Locked 400Hz & 1KHz (FM offset @1KHz!) BNC O/P
External BNC I/P into 5Kê 10Hz-30kHz
USES
As well a FM & AM demos on Ham training courses, I use it for setting up RF Rx.
And with an external "off air ref", it can generate any frequency to very high
accuracy.
See my tech Buls on "Syston Donner 115 Pulse Gen", "198kHz Off Air Standard",
"Comparing Off Air Freq Standards", "Off Air Lock for Ref Osc" & "Scope RF
Trick".
Why don't U send an interesting bul?
73 de John, G8MNY @ GB7CIP
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