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G8MNY > TECH 12.10.15 10:31l 158 Lines 7518 Bytes #999 (0) @ WW
BID : 44766_GB7CIP
Read: GUEST
Subj: Analyser Takeda Riken TR4122B
Path: IW8PGT<IZ3LSV<IK6ZDE<I0OJJ<GB7CIP
Sent: 151012/0919Z @:GB7CIP.#32.GBR.EURO #:44766 [Caterham Surrey GBR]
From: G8MNY@GB7CIP.#32.GBR.EURO
To : TECH@WW
By G8MNY (New Oct 15)
(8 Bit ASCII graphics use code page 437 or 850, Terminal Font)
I bought this rather large & very heavy vintage Japanese Spectrum Analyser &
Digital Store for "a song" at a club junk sale. It was not known how well it
worked, but I had seen it switched on at a test evening.
Vernier Freq
ÚÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄ¿
CRT ³oÚÄÄÄÄÄÄÄÄÄÄÄÄÄ¿ ³~~~~~~³( O )³Freq
Controls³o³ ³ øÀÄÄÄÄÄÄÙ ³
³o³ ³ . Ü_ ß- ³
³.³ DISPLAY ³ ú ³Scan &
³.³ ³ ( O ) ( O ) ³Bandwidth
On Off³O³ ³ Ü_³
³ ÀÄÄÄÄÄÄÄÄÄÄÄÄÄÙ ³Vid Filter
Presets³. . . ÚÄÄÄÄÄÄÄ¿ ³
³. . . ³Counter³ ( O ) (0) 0³Cal Out
Tracking³ ÀÄÄÄÄÄÄÄÙ . _Ü_ ³
Gen Out³(ú) () Ü Ü Ü Ü Ü o . _Ü_ (ú)³RF In
ÀÂÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÂÙ
³ Ü_ O {} {} [}{}{}{} ³
ÀÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÙ
Phones Digial store unit
It came with no information or front cover, but here is my spec for it so far..
FEATURES
Freq : DC-1500MHz,
Input : +20dB (100mW) Max, N input, 0-50dB atten
IF B/W : 300 100 50 10 1k 500Hz.
IF Gain: 0-50dB in 0dB & Calibrated 12dB Pot.
Cal : BNC with 200MHz @ -30dBm.
Sweep : 2kHz-100MHz/Div (link to B/W). Sweep stop for envelope & Phones use.
Marker : Movable spot with 8 digit Frequency Counter.
Phones : AM 3.5mm jack, AM & FM switched 6mm jack on memory unit.
Modes : Trace (U sweep spot) / Manual select sweep speed / Auto.
Display: Linear / 2dB/Div, / 10dB/Div Log.
Gen : Tracking Generator, optional band filters. 0-50dB atten, N output.
Store : 2 Digital memories & can be subtracted.
Output : 10.7MHz IF, X Y & Z for a 2nd Display.
Power : 122VA selectable AC Voltage / External DC (unknown Volts)
Weight : >25kg.
TESTING IT
Well is was very cheap, so I expected the odd problem, I soon saw one, the
precision input atten was broken, the first 10 20 & 30dB steps were OK, but 40
& 50dB fell off the screen. It was DC isolated to the N socket, so to I had to
open it up & unbolt bits to get further.
REPAIR
I located the input attenuator, to find it was a SMA connected remote relay
controlled module after the N input. On testing I found all the control lines
were going on & off so, it was not a control switch or relay drive logic fault.
Removed it & took the RF cover, I saw inside 6 tiny uWave relays & 3 RF
attenuators & track line on the RF substrate. As it was fairly symmetrical I
was be to identify in open circuit deposited R only 2mm square, on the input
side of the offending 20dB (40/50dB) attenuator. So it had been burnt out
(luckily only the attenuator & not the RF input!) Searching Jessops G6JP RADIO
DATA book, I found the theoretical value was 41R. I initially solder tinned the
silver strip lines either side of the faulty R & tried a wired resistor of 47R,
that out proved OK, this was the fault!
So for a proper job the 41R had to be accurate & small if I wanted the repair
to work well & be flat to 1500MHz. I used 3 surface mount Rs in parallel 2x
100R & a 220R to give the 41R. Once stacked up & soldering together the SM Rs
were not too difficult to solder to the pre-tinned stripline although a bit
messy in the end.
Success re-assemble & testing now showed nice even steps of the 50dB range &
all exactly 10dB & quite flat to 1500MHz with no surprises when the attenuators
are used.
THE 20dB RELAY ATTENUATOR
ÚÄ27R´ 2 double change over relays are
_____ o ÚÄ27R´ used 1 & 2 this ensures high
o \1b 2a o isolation with 4 contacts bypassing
SMA o)_/ 1a o______/ o___o 2b the through path when attenuating.
Input³ o \___To Next
³ ÀÄ41RÄÄÂÄÂÄÄ41RÄÂÄÄÄo Atten Unused paths terminated with 27R.
50ê ³ 20R 20R trimR
ÀÄÄÄÄÄÄÄÄÄÁÄÁÄÄÄÄÄÄÁÄÄÄÄÄÄÄ The fixed trimR used in calibration?
CALIBRATION
With the internal 200MHz -30dBm Calibrator, Input Attenuator, Frequency & Sweep
you can check & set the front panel CRT Preset Geometry Shifts & Gains. And
then do the 4 preset Shift & Gains on the side of the memory unit.
CRT DISPLAY
Log
dB Lin
0ÂÄÂÄÂÄÂÄÂÄÂÄÂÄÂÄÂÄÂÄÂ100% Long persistent White/Blue Phosphor & an
10´ Ã90% internal etched graticule viewed through a
20´ Ã80% clear thick blue glass give a clear display.
30´ Ã70%
40´ Ã60%
50´ Ã50%
60´ Ã40%
70´ Ã30%
80´ Ã20%
90´ Ã10%
ÁÄÁÄÁÄÁÄÁÄÁÄÁÄÁÄÁÄÁÄÁ0%
SCHEMATIC
As I do not have any information, so here is what I worked out from the
internal markings.
__________
Cal o)ÄÄÄÄÄÄÄÄÄÄÄ´200MHz OscÃÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄ¿
ÀÄÄÄÄÂÄÄÄÄÄÙ ________ ³
Track _____ _____³______ /³10,7 Osc³ ³ ______
Gen o)Ä´AttenÃÄÄ´ Gen Mixers ³ ÀÄÄÄÄÄÄÄÄÙ ³ ³ DC orÃÄDC
ÀÄÄÄÄÄÙ ÀÄÂÄÄÄÄÄÄÄÄÄÄÙ\________ ³ ³MAINS ³
_______ ÚÄÄÄÄÄÁÄ¿ _______ ³411 Osc³ ³ ³ PSU ÃÄ230V
³ Gated ³³ Sweep ô Sweep ³ ÀÄÄÄÂÄÄÄÙ ³ ÀÄÄÄÄÄÄÙ
³CounterôUHF Osc³³Control³ ³ ³
ÀÄÄÄÄÄÄÄÙÀÄÄÄÄÂÄÄÙÀÂÄÄÄÄÄÄÙ ³ ³
_____ ÚÄÁÄÄ¿ ³ ÚÄÄÄÄÄ¿ ÚÄÄÁÄ¿ ÚÄÄÄÄÄ¿ ÚÄÁÄÄ¿ ÚÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄ¿
In o)Ä´AttenÃÄÄ´Mix1ÃÄ)Ä´613IFÃÄ´Mix2ÃÄ´210IFÃÄ´Mix3ÃÄ´10.7IF & Filtersÿ
ÀÄÄÄÄÄÙ ÀÄÄÄÄÙ ³ ÀÄÄÄÄÄÙ ÀÄÄÄÄÙ ÀÄÄÄÄÄÙ ÀÄÄÄÄÙ ÀÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÙ³
ÚÄÄÄÄÄÄÄ¿ ÚÄÄÄÄÄÁÄÄÄÄÄÄÄ¿ ÚÄÄÄÄÄÄÄÄÄÄÄÄ¿ ÚÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄ¿ ³
³DISPLAYÃÄÂÂÄ´DIGITAL STOREÃÄÄ´Video FilterÃÄÄÂÄÄ´Lin/Log DetectorÃÄÄ´
ÀÄÄÄÄÄÄÄÙ ³³ ÀÄÄÄÄÄÄÄÄÄÄÄÄÄÙ ÀÄÄÄÄÄÄÄÄÄÄÄÄÙ ³ ÀÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÙ ³
X o)ÄÄÄÄÄÄÄÄÄÙ³ PSU ______ ³ ____________ ³
Y o)ÄÄÄÄÄÄÄÄÄÄÙ oÄÄÄÄÄÄ´AM AMPÃÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÙ ³FM Det & AmpÃÄÄÄÄÄÙ ³ ____________ ³
Phones o)ÄÄÄÄÄÄÄÄ\o ÀÄÄÄÄÄÄÙ ÀÄÄÂÄÄÄÄÄÄÄÄÄÙ
ÀÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÙ
IN USE
Compared to home made & simper commercial Spectrum Analyser I have used, this
"Proper one" takes some getting use to. With the multiple bandwidths available
from 3MHz for fast sweeps right down to 500Hz close in work. The inter-lockable
Sweep & Bandwidth control & the Auto sweep speed, stops you getting a faulty
spectrum display. But as this is not a modern PLL system, slow drift of the
swept UHF Yig(?) oscillator is quite noticeable on close in work. but it does
almost stop after 1 hr warm up. One shot sweeps with memory solve this drawback
too. With slow sweep, narrow bandwidth, video filter in & the storage memory,
the noise floor is then seen at 88dB down with a near overloading input.
The tacking generator is very useful on filters & pre-amps etc, but the first
thing you notice is all your bad cables & connectors! Of course it can also be
used just a sweep gen too, triggering a scope from Z out etc.
The 2 memories can be used in subtraction mode, so a change in display can be
seen, or an un-flat response of test leads normalised before a measurement.
FURTHER INFORMATION
I wonder if any readers have used this SA or have any information on it?
Why don't U send an interesting bul?
73 de John G8MNY @ GB7CIP
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