| |
G8MNY > TECH 26.07.03 09:50l 27 Lines 1218 Bytes #999 (0) @ WW
BID : 7137_GB7CIP
Read: GUEST DB0FHN OE7FMI
Subj: SYSTRON DONNER 1702 SIG Gen?
Path: DB0FHN<DB0RGB<DB0MRW<DB0FOR<DB0SIF<DB0GV<DB0ZDF<DB0LJ<LX0HST<HA3PG<
7M3TJZ<IK1ZNW<GB7CRV<GB7CIP
Sent: 030725/2349Z @:GB7CIP.#32.GBR.EU #:7137 [Caterham] $:7137_GB7CIP
From: G8MNY@GB7CIP.#32.GBR.EU
To : TECH@WW
Hi & thanks for reading.
I bought one of these large digital signal generators at the Leicester
rally a few years ago. It is 19" rack sized & generates signal in 100Hz steps
from from 100Hz - 999.9999MHz with 8 lever operated thumb wheels. It was made
in the USA by the Throrn EMI owned SYSTRON DONNER Co. in 1983?
It uses several PLL oscillators & mixers, all locked to an internal/external
reference. It has a calibrated AM & FM modulation (digital readout) display
from built in locked 400Hz & 1KHz sine wave sources as well as external mod.
Unfortunatly it was not all working (eg no 144MHz) when I got it, but I have
now managed to repair all the faulty bits I think, without a diagram! Which was
very time consuming, working out how it all worked (internal silvered brass RF
unit and 16 PCBs in all)!
I have done several mods to it now. eg FM deviation increased to 100KHz, & mod
bandwidth imporved & a "poor man's Ceasium ref" (simular to BATC/Radcom) where
I have phase locked the 1MHz master crystal oscillator to BBC terrestial TV
line syncs, to give around 1 in 10^11 accuacy!
I would appreciate any information on the unit.
73 de John, G8MNY @ GB7CIP
Read previous mail | Read next mail
| |
