> menu inklappen <
 algemeen
 adressen/contacten
equipment buy/sell
fail-gallery
 press information
for sale!
weblog/news
apparatuur foto's
Elcom PAN2000
HP 331A distortion analyser
Leader LDM-815 dipmeter
Philips PM2524 multimeter
Rigol DS-1054Z
Sayrosa 261 frequency counter
Schlumberger FS30 / FSM500
banden
27Mc
FRS
LPD
PMR
componenten
(E)EPROM
crystals
resistor coding
connectoren
12VDC connector
coax connectors
Racal Cougar
0. Racal Cougar
1. introduction
2. compnents
 3. assemblies
4. technical
5. modifications
6. data protocol
7. service
documentatie
books
FUP1DZ manual
jargon
Morse code
NATO alphabet
Q-codes
radio notebook
serial port/RS232
elektronenbuizen
6H2N-EB / 6N2P / ECC83 / 12AX7
algemene informatie
ATP4 elektronenbuis
elektronenbuis codering
elektronenbuizen
gloeistroom/-spanning
IV-25 dot bar VFD
reactiveren/reformeren
stabilisatiebuizen
filters/combiners
23 cm duplex filter
Aerial Facilities BPD-410/420-3N
Celwave P522 UHF duplexer
Hoxin DX-720 diplexer
JWX triplexer broadcast/VHF/UHF
Kenwood LF-30A LPF
Motorola UHF cavity combiner
Radiosystem RS460 cavity BPF
stub filter
basics: diplexer or duplexer
legerzenders
AM-65/GRC
LV-80 RF PA
SEM antennetuner (AGAT)
SEM25 gloeispanning
SEM25 transceiver
SEM35
mechanica
lathe
krimplak
schroefdraad
verspanen
meetapparatuur
10/20/30 dB RF attenuator
Agilent 8591C
BG7TBL 10 MHz bandpass filter
BG7TBL noise source
Daiwa CN-101L
Daiwa CN-801
HP 8782B vector signal generator
HP P382A verzwapper
impedance converter 50/75 Ohm
x-tal tester (DIY project)
Krohn-Hite 4100 signal generator
Marconi 2955A
Marconi TF2163
Radiosystem AB dummy load
Rigol DSA815-TG
Rohde & Schwarz CMT54
Rohde & Schwarz CMU200
Rohde & Schwarz ZVM
Rohde&Schwarz SMT 02
Spinner dummyload
Zetagi DL50 dummyload
tijdstandaard/GPSDO/OSC
10 MHz distribution amplifier
10 MHz low pass filter
BG7TBL GPSDO
Frequency Electronics FE-5680A
GPSDO time display
HP 10811 OCVCXO
leap second
RS920 10MHz oscillator
timestandard (general)
tijdstandaard; VE2ZAZ
time standard; W5OJM
Trimble 34310-T OCVCXO
Yaesu FT-8x7 (TC)XO
meetapparatuur (info)
(poor mans) spectrum analyser
dummyload
frequentieteller
functiegenerator
meetverzwakker
octopus component tester
oscillator adjustment
staandegolfmeter
Step Attenuator
test- en meetapparatuur
modificaties
Counter 1 MHz input mod.
Icom IC-756PRO fan mod
Yaesu FT-897/FT-897D
Yaesu MH-48 lock mod
naslagwerk
(coax) kabels coderen
AWG wire table
coax kabels testen
checking, cleaning and overhauling
DTMF
Yaesu FT-8x7 CAT port
paneelbouw
s-meter
Selcall / 5TVO
output impedance
projecten
afregelen FT-8x7(D)
counter prescaler
CTCSS module
FT-2000 headset
FT-2000 remote
FUP1DZS meetzender
Geloso G.1/1040-A
Geroh AKAC019 liermast
go-kit
go-kit FT-7800
headset (Avcomm)
RF power amplifier
hoofdtelefoon versterker PL500
Icom IC-25E
Kerona AR-301 rotor
KLV 400 RF PA ombouw
MFJ-948 antenna tuner
Nixie clock
parallelle poort controller
Pixie CW TX
programmeren FT-8x7
TH-D7E tracker
uTracer 3+
VSWR SA meetbrug
Yaesu FT-857/897 meter
zwaai Alinco DR-135E MkII
publicaties
elektromigratie in filters
Ruisvrij squelch schakelen
SINAD
radioapparatuur
Ameritron ATR-20 tuner
Baofeng UV-5R
Diamond X-30N antenna
Icom IC-2e
Icom IC-705
Icom IC-706
Icom IC-7100
Icom IC-7300
Kenwood TH-D7E
Kenwood TS-830M
Logper antenna 1,35...9,5 GHz
MFJ-901b antennetuner
MFJ-948 antennetuner
MFJ-971 antenna tuner
QYT KT-8900
Telefunken ELK 639
Triple-P TXU-1256 repeater
Wouxun KG-UVD1P
Wouxun speakermike
Yaesu FT-101E
Yaesu FT-1500M
Yaesu FT-1802
Yaesu FT-2000
Yaesu FT-2800M
Yaesu FT-7800
Yaesu FT-817
Yaesu FT-857(D)
Yaesu FT-897(D)
Yaesu FT-8x7 serie
Yaesu FT-991
voedingen
Maas/KPO/Manson SPA-8230 voeding
Samlex SEC 1223 voeding
reparaties
capacitors
Geloso 3227 versterker
Icom IC-706mkIIG
Kenwood TS-830M
LeCroy waveAce 2004
Lorenz SEM25
Yaesu FT-817
Yaesu FT-897D
schakelingen
elektret microphone
Time Domain Reflectometer
surplus apparatuur
BBC Vericrypt 1100
Motorola GM950 (70 MHz)
Polyphaser
Racal VRM5080
Rohill R-2050
Teletron/Condor
Teltronic M-250
telefonie surplus
Ericsson F-955
Ericsson F-955 modifcations 2017
Ericsson RS203/RS2062
Radiosystem monitoring unit
Radiosystem RS950
Radiosystem RS951
Rohde & Schwarz CMD53
gereedschap
Minipro TL866 programmer
Velleman VTSSC50N soldering station
Yihua 852D+ soldeering station
ZD-409 desoldering tweezer
ZD-915 desoldering station
theorie
aarding
antennetuner
waves
snubber diode
EMC/EMI
9/150 kHz HPF
decoupling capacitors
ESH2-Z5 LISN
Line Impedance Stabilisation Network
werkplek
component archive
soldering
workshop tips
veiligheid
Beryllium oxide
EM veldsterkte
radioactiviteit
harardous radiation?
avionica
Avionics safety!
Smiths Radio Altimeter
Ferranti FTS 21T turn and slip indicator
VDO ST443-3 Nozzle Area Position Indicator
Tornado TV TAB DU: introduction
Tornado TV TAB DU: original use
Tornado TV TAB DU: frame module
Tornado TV TAB DU: wire harness
Tornado TV TAB DU: keyboard module
Tornado TV TAB DU: CRT module
Tornado TV TAB DU: LVPS
Tornado TV TAB DU: HVPS
Tornado TV TAB DU: A1 PCB
Tornado TV TAB DU: A2 PCB
Tornado TV TAB DU: A3 PCB
Tornado TV TAB DU: A4 PCB
Tornado TV TAB DU: A5 PCB
Tornado TV TAB DU: A6 PCB
Tornado TV TAB DU: reverse eng.
overig
Gamma Scout
PI3WAD V1
SV500 radiation meter
|
|
introduction
|
permalink: http://www.amateurtele.com/index.php?artikel=221&id=#970
|
Since a couple of years I'm the proud owner of a Sayrosa model 261 frequency counter. It's a great device. The brand is quite unknown and I haven't seen any other device from Sayrosa. The counter can count until 600 MHz which's quite nice. There's an internal "OCXO". Well, it's a crystal with a heating element attached to it, but since I have a GPSDO time standard I want to use the generated stable 10 MHz signal for reference. Luckily there's an external female BNC clock signal input. Unfortunately the desired frequency is 1 MHz instead of 10 MHz. I'm designing a distribution device for the 10 MHz signal. The distributor should get eight selectable outputs. The selection is 10, 5 and 1 MHz and is should be possible to select a sinewave of square wave signal. But I guess the designing and building will take quite some time due to other priorities. Therefore I want to modify the frequency counter so it can handle the more standardised 10 MHz clock signal.
|
|
initial design
|
permalink: http://www.amateurtele.com/index.php?artikel=221&id=#971
|
I made a sketch of the desired circuit. The "heart" of the circuit is a 74LS390 chip (or related model like HC or HCT instead of LS) which is great for this purpose since it can divide by five and two! Therefore the 10 MHz signal can be divided by both and the result is the desired 1 MHz signal. Remind that the "divide by five" signal is a pulse signal and not a square wave. Dividing the 2 MHz signal by two "corrects" the signal to a nice (and desired) square wave. To terminate the 50 Ohms coax cable I've drawn a 47 Ohms resistor. (One 50 Ohms resistor or two 100 Ohms resistors in parallel would even be better. Normally a logic chip has a switching threshold of half the supply voltage. For example the switching threshold of a 5 VDC powered chip is normally 2,5 VDC. Therefore I've drawn two rather large (10 K) resistors to bias the input signal to 2,5 VDC. To decouple the 10 MHz RF signal is added one 470 pF capacitor. Since the logic signal is a square wave (sinewave with infinite harmonics) and I want a "perfect" sinewave I added a five pole 1 MHz low pass filter to suppress harmonics. The harmonics should be supressed at least 48,2 dBc. At first I wanted to be able to switch between the original 1 MHz signal and 10 MHz signal. But I can't imagine that I want to feed the counter with a 10 MHz signal and therefore the switch is discarded.
|
|
real world circuit
|
permalink: http://www.amateurtele.com/index.php?artikel=221&id=#972
|
The oscillator signal is directly fed into a divider chip and therefore the low pas filter and decoupling capacitor can be discarded form the design. Also the two resistors are replaced by a variable resistor. Apparently this chip has a threshold voltage of approximately 1,3 VDC. It turned out that two fixed resistors was too much of a hassle to get it right so I used a 10 kOhms variable resistor. For the middle region of the resistor the bias an be set quite nice. (Near 5 VDC and ground is the signal strength weakened.) The input’s of the not used dividers (the chip has more dividers on board than shown on the schematic) are connected to ground to prevent unwanted oscillations. The ground pins if the chip is soldered directly to the reference plane (ground plane) of the printed circuit board. The other components are soldered like the "dead bug" method to the chip. After setting the bias voltage, the circuit works great! There's an original switch on the back of the radio so the internal or external clock source can be selected. Therefore the counter can be used without an external clock signal.
|
|
