The Electron of September delivered today showed the Dutch VERON DX Honor Roll per July 2013. I found myself on position 286 of the list with 128 different DXCC's.
Not that bad for a modest set-up I use and the time I spend on making HF QSO's.
I started about 8 years ago on shortwave with a tube (2x 6164) rig TS515, then switched to a TS130 and last 3 years I use a Yaesu FT450. Also contacts with QRP homemade equipment were made. Most of the time with a simple G5RV jr antenna (2 x 7.75 m) over the roof of my house.
I started to make lots of digimode contacts (PSK31 in particular). During contests SSB and RTTY are the most used modes.
It is amazing to see that nr 1 till nr. 21 of the list all worked 340 DXCC's.
The TS515 I used around 2005
The FT450 (without internal antenna tuner) that I use nowadays. Almost all of the time with less than 20 Watts RF.
Saturday, 31 August 2013
1.2 GHz 2 Watt PA, a begin
While waiting for the CLY15 to arrive, today I started with the PA for 1.2 GHz.
Used a simple unetched PCB to cut-out the striplines.
Decided to use SMA connectors instead of BNC. BNC runs appr. until 1 GHz.
In the back you see the 1-channel 1.2 GHz video module that provides 100 mW.
Next step: Components for the power supply on a seperate pcb. I installed 3 parallelled 7805 which make 3 Amps available at 5 Vdc and a 7905 for the adjustable -2...0 Vdc Vgs. Also the 3 varco's on the striplines have been added:
Used a simple unetched PCB to cut-out the striplines.
Decided to use SMA connectors instead of BNC. BNC runs appr. until 1 GHz.
In the back you see the 1-channel 1.2 GHz video module that provides 100 mW.
Next step: Components for the power supply on a seperate pcb. I installed 3 parallelled 7805 which make 3 Amps available at 5 Vdc and a 7905 for the adjustable -2...0 Vdc Vgs. Also the 3 varco's on the striplines have been added:
Thursday, 29 August 2013
CLY15
I would like to do some ATV trials in the 23 cm band. For this purpose I have a small ATV module that transmits on 1256 MHz with appr. 100 mW. This is not enough to reach the local ATV repeater PI6ZTM. Therefore I am looking for a PA to boost the 100 mW signal.
Lately I discovered the CLY15 GaAsFET. This FET is often used in GSM and WiFi equipment and is manufactured in large quantities.
It is able to produce appr. 2 Watts up till 2.4 GHz. It's very small (SOT223 housing). Power supply voltage is max. 6 Vdc.
I found that it requires a negative Gate Source voltage to operate.
Because this type of FET is so cheap ($2), I ordered 2 of them at eBay for some trials.
If less power is required, the CLY5 or CLY10 can be a better choice.
Lately I discovered the CLY15 GaAsFET. This FET is often used in GSM and WiFi equipment and is manufactured in large quantities.
It is able to produce appr. 2 Watts up till 2.4 GHz. It's very small (SOT223 housing). Power supply voltage is max. 6 Vdc.
I found that it requires a negative Gate Source voltage to operate.
Because this type of FET is so cheap ($2), I ordered 2 of them at eBay for some trials.
If less power is required, the CLY5 or CLY10 can be a better choice.
CLY 15 specs
Tuesday, 27 August 2013
73 from Birmingham
Just received a nice eQSL from the UK. On 40m I made a SSB QSO with Callum, August 17. He received my 15 Watts signal with 55. His signal was much stronger in Zoetermeer. Nice picture of Birmingham by night ! Wished all eQSL-users had their own pictures on the cards.
Sunday, 25 August 2013
10 mtr WSPR
Fair propagation this afternoon on 28 MHz.
Adjusted my FT450 to 28.12460 MHz this afternoon and set TX frequency in WSPR software to 28.126130 MHz.
RF Output power was 5 Watt into G5RV junior antenna .
Results were as follows:
Adjusted my FT450 to 28.12460 MHz this afternoon and set TX frequency in WSPR software to 28.126130 MHz.
RF Output power was 5 Watt into G5RV junior antenna .
Results were as follows:
Friday, 23 August 2013
PA2RF / Bike mobile
Today was a good day for out-of-the-house activities. Expected temperatures about 25 degrees Celsius, attic radioshack temperatures similar or even higher. I decided to enjoy the nice weather by grabbing my bicycle and make a nice trip into "Het groene hart" ("The green heart"). Finally it turned out to be a ride of appr. 29 km.
Of course I took with me some radio equipment: A JingTong 2m porto with 2 Watts output. Even about 15 km from my QTH Zoetermeer, I was able to make contact with the local repeater on 145.750 MHz, FM. I had two nice chats with Jack, PA7RJ. I found out that the JingTong porto works fine after not being used for allmost one year and 2 Watts is enough for smalltalk.
Switched on the app "MyTracks" on my smartphone (Samsung Galaxy Y) to record my track using the GPS satellites. It makes a nice track on Google maps as you can see in the picture above. I really recommend this app.
Some impressions of my bike ride today:
"De Wilck" 600 acres of protected environment
This is the place where your Heineken beer comes from. The factory is located in Zoeterwoude
These guys block my way...
Quiet area in the "Randstad "
Some statistics recorded by "MyTrack" ;
Totale afstand: 29,92 km (18,6 mi)
Totale tijd: 1:43:28
Verplaatsingstijd: 1:35:47
Gemiddelde snelheid: 17,35 km/u (10,8 mi/u)
Gemiddelde verplaatsingssnelheid: 18,74 km/u (11,6 mi/u)
Max. snelheid: 24,46 km/u (15,2 mi/u)
Gemiddeld tempo: 3,46 min/km (5,6 min/mi)
Gemiddeld verplaatsingstempo: 3,20 min/km (5,2 min/mi)
Snelste tempo: 2,45 min/km (3,9 min/mi)
Max. helling: 17 %
Min. helling: -15 %
Opgenomen: 23-09-2013 14:59
Verzonden vanaf Samsung Mobile
Of course I took with me some radio equipment: A JingTong 2m porto with 2 Watts output. Even about 15 km from my QTH Zoetermeer, I was able to make contact with the local repeater on 145.750 MHz, FM. I had two nice chats with Jack, PA7RJ. I found out that the JingTong porto works fine after not being used for allmost one year and 2 Watts is enough for smalltalk.
Switched on the app "MyTracks" on my smartphone (Samsung Galaxy Y) to record my track using the GPS satellites. It makes a nice track on Google maps as you can see in the picture above. I really recommend this app.
Some impressions of my bike ride today:
This is the place where your Heineken beer comes from. The factory is located in Zoeterwoude
These guys block my way...
Quiet area in the "Randstad "
Some statistics recorded by "MyTrack" ;
Totale afstand: 29,92 km (18,6 mi)
Totale tijd: 1:43:28
Verplaatsingstijd: 1:35:47
Gemiddelde snelheid: 17,35 km/u (10,8 mi/u)
Gemiddelde verplaatsingssnelheid: 18,74 km/u (11,6 mi/u)
Max. snelheid: 24,46 km/u (15,2 mi/u)
Gemiddeld tempo: 3,46 min/km (5,6 min/mi)
Gemiddeld verplaatsingstempo: 3,20 min/km (5,2 min/mi)
Snelste tempo: 2,45 min/km (3,9 min/mi)
Max. helling: 17 %
Min. helling: -15 %
Opgenomen: 23-09-2013 14:59
Verzonden vanaf Samsung Mobile
Poor man's programming
Yesterday I went for a quick fix to incorporate my own text in the PIC12F683 of the pico OSD.
Used the hex editor WinPic800 to change existing text to new text.
I would not call this programming, it's just changing ASCII hex codes. Anyway, the result looked ok. My callsign, QTH locator and elapsed time come in view superimposed on a PAL video signal (e.g. from camera, DVD player)
Screenshot WinPic800
TV screen 1
TV screen 2
I am considering to download Microchip's development environment MPLAB IDE and a trial version of Hi-Techs C-compiler for small PICs to try some real programming. Four 2K Eeprom PICs 12F683 have already been ordered from eBay (total of $3.00 incl. shipping from China :-) ).
Hope to do some testing coming weekend with a small ATV transmitter (100 mW) and biquad antenna. Coming period I won't have much time for the hobby since the end of my holiday is approaching and the QRL starts to pull.
Used the hex editor WinPic800 to change existing text to new text.
I would not call this programming, it's just changing ASCII hex codes. Anyway, the result looked ok. My callsign, QTH locator and elapsed time come in view superimposed on a PAL video signal (e.g. from camera, DVD player)
Screenshot WinPic800
TV screen 1
TV screen 2
I am considering to download Microchip's development environment MPLAB IDE and a trial version of Hi-Techs C-compiler for small PICs to try some real programming. Four 2K Eeprom PICs 12F683 have already been ordered from eBay (total of $3.00 incl. shipping from China :-) ).
Hope to do some testing coming weekend with a small ATV transmitter (100 mW) and biquad antenna. Coming period I won't have much time for the hobby since the end of my holiday is approaching and the QRL starts to pull.
Wednesday, 21 August 2013
Video switch ready
I finished the video switch/pattern generator.
This box enables me to select (2) external inputs or a test pattern bar and make the signal available on the cinch output bus.
On top of the external video signals, the pico OSD superimposes the elapsed time.
Main components used for this device:
CD4060 => pattern generator
TEA2014A => video switch
PIC 12F683 => pico OSD
After all this gadget did not cost me that much:
Housing and mains connector/switch : retrieved PSU housing from old PC. Had to paint it. TEA2014A : from old Samsung TV pcb
PIC 12F683 : bought from eBay $1.20
CD4060 and most components : junk box
Application TEA2014A
Since the "LF" part is more or less finished, now I am ready to start with the RF part of the ATV 1.2 GHz transmitter.
Still one wish: Reprogramming the PIC 12F683 to make my callsign and QTH locator visible below the elapsed time of the pico OSD. I have to study " C " language and find a suitable C-compiler to do this.
Test pattern
One of the two external inputs with time elapsed info from the pico OSD
This box enables me to select (2) external inputs or a test pattern bar and make the signal available on the cinch output bus.
On top of the external video signals, the pico OSD superimposes the elapsed time.
Main components used for this device:
CD4060 => pattern generator
TEA2014A => video switch
PIC 12F683 => pico OSD
After all this gadget did not cost me that much:
Housing and mains connector/switch : retrieved PSU housing from old PC. Had to paint it. TEA2014A : from old Samsung TV pcb
PIC 12F683 : bought from eBay $1.20
CD4060 and most components : junk box
Application TEA2014A
Since the "LF" part is more or less finished, now I am ready to start with the RF part of the ATV 1.2 GHz transmitter.
Still one wish: Reprogramming the PIC 12F683 to make my callsign and QTH locator visible below the elapsed time of the pico OSD. I have to study " C " language and find a suitable C-compiler to do this.
Test pattern
One of the two external inputs with time elapsed info from the pico OSD
Tuesday, 20 August 2013
pico OSD
In order to be able to add information to my PAL video signals I looked for a simple
circuit that can do that. I found the PicoOSD (" Overlay Superimposer Device ").
This circuit with only a tiny 12F683 PIC superimposes information
(like text and clock info ) over an existing PAL composite video picture.
I built the experimental circuit (which is only the pic, 25 MHz xtal and 2 15 pF capacitors) on a breadboard.
After programming the 12F683 the circuit worked immediately.
In the picture you see on top of the screen the elapsed time info. This is what the pico-osd does.
The clock info on top of the screen comes from the pico OSD. I am impressed!
Now the real challenge comes with reprogramming the source code in order to make my callsign and QTH locator visible. Not so easy since the program is written in " C ".
Experimental OSD on breadboard
Also have soldered the circuit on a piece of veroboard and now must integrate
the small circuit into the existing video switch/pattern generator.
OSD on vero-board
All the details:
http://www.micro-examples.com/articles/index.php/PicoOSD
Compliments to Bruno Gavand who develloped this project. Amazing what a 50 cents PIC can do for you !
Elapsed time shown on scene of "Bladerunner" with Rutger Hauer
circuit that can do that. I found the PicoOSD (" Overlay Superimposer Device ").
This circuit with only a tiny 12F683 PIC superimposes information
(like text and clock info ) over an existing PAL composite video picture.
I built the experimental circuit (which is only the pic, 25 MHz xtal and 2 15 pF capacitors) on a breadboard.
After programming the 12F683 the circuit worked immediately.
In the picture you see on top of the screen the elapsed time info. This is what the pico-osd does.
The clock info on top of the screen comes from the pico OSD. I am impressed!
Now the real challenge comes with reprogramming the source code in order to make my callsign and QTH locator visible. Not so easy since the program is written in " C ".
Experimental OSD on breadboard
Also have soldered the circuit on a piece of veroboard and now must integrate
the small circuit into the existing video switch/pattern generator.
OSD on vero-board
All the details:
http://www.micro-examples.com/articles/index.php/PicoOSD
Compliments to Bruno Gavand who develloped this project. Amazing what a 50 cents PIC can do for you !
Elapsed time shown on scene of "Bladerunner" with Rutger Hauer
Sunday, 18 August 2013
14 MHz WSPR
With 5 Watts on 20m this morning, I did some WSPR-ing. Lots of stations were active in this mode worldwide. It is always amazing to see how far the weak QRP radiosignals travel:
Allthough RTTY signals (contest going on) spoilt this part of the 20m band, no problems were encountered during the decoding proces.
Allthough RTTY signals (contest going on) spoilt this part of the 20m band, no problems were encountered during the decoding proces.
Saturday, 17 August 2013
40m LSB QSO with Scotland
Just made a nice QSO with Richard, GB2LK from Scotland on 7187 kHz.
This is a lighthouse station in the south-west of Scotland. Richard used a wire antenna and had 200 Watts in the air while I was using 25 Watts from my Yaesu set. He received my small radiosignal with S57.
The Scottish landscape where the lighthouse is located is impressive, have a look yourself:
http://qrz.com/db/GB2LK
Since it is the International Lighthouse-Lightship weekend there is a lot of activity from stations located on the lighthouses/ships.
Later this evening also worked John, GB0REL from Northern Ireland,
Grid Square IO65VH
This is a lighthouse station in the south-west of Scotland. Richard used a wire antenna and had 200 Watts in the air while I was using 25 Watts from my Yaesu set. He received my small radiosignal with S57.
The Scottish landscape where the lighthouse is located is impressive, have a look yourself:
GB2LK (LIGHTHOUSE KILLANTRINGAN)
Nr Portpatrick, Dumfries & Galloway, SW Scotland.
ILLW No: UK0164 ARLHS No: SCO111
Loc: IO74ku WAB: NW95 CQ Zone: 27 ITU: 14
http://qrz.com/db/GB2LK
Since it is the International Lighthouse-Lightship weekend there is a lot of activity from stations located on the lighthouses/ships.
Later this evening also worked John, GB0REL from Northern Ireland,
Grid Square IO65VH
Thursday, 15 August 2013
JT9-1
This afternoon I made two digimode QSO's in JT9-1 with the Yaesu FT450 while JT9 software was running on my old PC from 2007.
Frequency 14.078 MHz. RF power, QRP level, 5 Watts.
The first QSO was with Jacques, F1VEV from St. Valier.
The second with Spain, Antonio, EA7HJ.
Compliments to Joe, K1JT, the designer of this interesting weak signal mode.
Frequency 14.078 MHz. RF power, QRP level, 5 Watts.
The first QSO was with Jacques, F1VEV from St. Valier.
The second with Spain, Antonio, EA7HJ.
Compliments to Joe, K1JT, the designer of this interesting weak signal mode.
DIY video pattern generator
For future ATV experiments I was looking for a (simple) video pattern generator (PAL format), The internet learned me that there are several (expensive) special purpose ic's for this function. Also PIC-based projects are available. The search brought me also to this circuit:
This must be one of the simplest video pattern generators one can realize. It provides a black/white bar pattern. The circuit is designed around a 1$ 4060. This is a 14 bit counter.
A steps shaped block wave is created by adding the 3 output signals (contacts 4, 5 and 7) in the proper proportions.
The output signal can be adjusted to the required 1 Volt peak-peak. Contact 4 (Q5) provides a f:64 signal. When the Xtal is choosen as 1 MHz, output Q5 delivers a 15,625 Hz signal. This is what is required for the 64 us synchronization pulse (0 V).
I did trials with various Xtal frequencies and 4.43.. MHz provide three main bars each consisting of 8 subbars. I presented this signal to a small QRP ATV 1.2 GHz transmitter and when received by an analogue satellite tuner, the picture above was seen on my TV.
The circuit was realized according to the " dead-bug " rules:
If you know how a simpler video generator can be made than presented here, I am very interested.
Typical PAL video signal providing a bar pattern:
This must be one of the simplest video pattern generators one can realize. It provides a black/white bar pattern. The circuit is designed around a 1$ 4060. This is a 14 bit counter.
A steps shaped block wave is created by adding the 3 output signals (contacts 4, 5 and 7) in the proper proportions.
The output signal can be adjusted to the required 1 Volt peak-peak. Contact 4 (Q5) provides a f:64 signal. When the Xtal is choosen as 1 MHz, output Q5 delivers a 15,625 Hz signal. This is what is required for the 64 us synchronization pulse (0 V).
I did trials with various Xtal frequencies and 4.43.. MHz provide three main bars each consisting of 8 subbars. I presented this signal to a small QRP ATV 1.2 GHz transmitter and when received by an analogue satellite tuner, the picture above was seen on my TV.
The circuit was realized according to the " dead-bug " rules:
If you know how a simpler video generator can be made than presented here, I am very interested.
Typical PAL video signal providing a bar pattern:
Tuesday, 13 August 2013
NAVTEX 518 kHz
At regular intervals on 518 kHz NAVTEX messages are transmitted by various coast stations.
NAVTEX stands for (NAVigational TEXt messages). This radiotelex service transmits navigation and meteo warnings and Search and Rescue messages.
Of course you can use a dedicated NAVTEX receiver but if you have a general receiver that can be tuned to 518 kHz in SSB, than you can receive and decode NAVTEX messages.
My FT450 is capable of receiving this frequency. I used a simple magnetic loop antenna
made of 11 turns of wiring around 4 nails inside the attic roof. This antenna using a 150 pF variable capacitor is capable of receiving 470-520 kHz (includes the 600 m ham band).
NAVTEX uses the AMTOR FEC mode. This code is supported by MultiPSK.
The NAVTEX coast stations not too far from my QTH could be received and decoded (Oostende, Dutch coastguard). In Sweden, Grimeton there is also a NAVTEX transmitter.
The coaststations transmit in a tight schedule, every 10 minutes another station takes over the transmission.
More info;
http://www.scannernet.nl/navtex/info-navtex.html
http://nl.wikipedia.org/wiki/Navtex
Also, find below the comments of Jan, PA3ABK with tips for additonal software capable of decoding NAVTEX information/signals.
NAVTEX stands for (NAVigational TEXt messages). This radiotelex service transmits navigation and meteo warnings and Search and Rescue messages.
Of course you can use a dedicated NAVTEX receiver but if you have a general receiver that can be tuned to 518 kHz in SSB, than you can receive and decode NAVTEX messages.
My FT450 is capable of receiving this frequency. I used a simple magnetic loop antenna
made of 11 turns of wiring around 4 nails inside the attic roof. This antenna using a 150 pF variable capacitor is capable of receiving 470-520 kHz (includes the 600 m ham band).
NAVTEX uses the AMTOR FEC mode. This code is supported by MultiPSK.
The NAVTEX coast stations not too far from my QTH could be received and decoded (Oostende, Dutch coastguard). In Sweden, Grimeton there is also a NAVTEX transmitter.
The coaststations transmit in a tight schedule, every 10 minutes another station takes over the transmission.
More info;
http://www.scannernet.nl/navtex/info-navtex.html
http://nl.wikipedia.org/wiki/Navtex
Also, find below the comments of Jan, PA3ABK with tips for additonal software capable of decoding NAVTEX information/signals.
Monday, 12 August 2013
Train incident
Very, very off-topic, I know, but this is what happened on my railroad tracks a couple of weeks
ago:
No casualties. Everybody survided the crash :-)
The Santa Fe loc started to move by itself (" uncontrolled") and hit the German e-loc " Speisewagen ".
Model trains are another hobby (since I was 6 years old or so..) on which I spend some hours now and then.
I guess this incident must have been caused by a lack of communication...
No casualties. Everybody survided the crash :-)
The Santa Fe loc started to move by itself (" uncontrolled") and hit the German e-loc " Speisewagen ".
Model trains are another hobby (since I was 6 years old or so..) on which I spend some hours now and then.
I guess this incident must have been caused by a lack of communication...
Saturday, 10 August 2013
Uniden 2m transceiver
While surfing the internet in 2011, I visited www.2dehands.nl/zendamateur
The transceiver section showed a transceiver that was very familiair to me:
The 145 MHz FM transceiver Model 2030 from Uniden (made in Japan). This set is
designed for mobile use and offers 12 channels in the 2 meter band making
transmissions with 10 Watts RF possible.
With a similar 2m set (Zodiac Gemini) and a Ferranti 2m Yagi I made my first 2m FM
QSOs in 1980/1981 when I still lived in de Betuwe (Culemborg). At that time I had
a limited D-licence; you were only allowed to work on 6 frequencies in FM in
the 2m band. Since the price of the used set was acceptable I immediately ordered
the rig.
After being delivered by TNT-post, incl. 'operation manual 'I connected the Uniden 2030
to a simple GP antenna. After some CQ's on 145.500 MHz, PA65L from Leiden responded.
Everything worked fine !
No frequency synthesizers or PLL in this rig, but 12 discrete Xtal positions. That's how
it was done in the late 70's.
Crystal positions are as follows:
1) 145.250 MHz
2) -
3) 145.500 MHz
4)-
5)-
6) 145.400 MHz
7) 145.175 MHz
8) 145.000 MHz
9) 145.100 MHz
10) 145.050 MHz
11) 145.200 MHz
12) 145.075 MHz
The Uniden has a switch to set the output power; you can select 1 or 10 Watts.
The transistor producing 10 Watts is a 2SC1605A. An 'automatic protection circuit'
assures that the PA is switched off when the SWR becomes too high.
The transceiver section showed a transceiver that was very familiair to me:
The 145 MHz FM transceiver Model 2030 from Uniden (made in Japan). This set is
designed for mobile use and offers 12 channels in the 2 meter band making
transmissions with 10 Watts RF possible.
With a similar 2m set (Zodiac Gemini) and a Ferranti 2m Yagi I made my first 2m FM
QSOs in 1980/1981 when I still lived in de Betuwe (Culemborg). At that time I had
a limited D-licence; you were only allowed to work on 6 frequencies in FM in
the 2m band. Since the price of the used set was acceptable I immediately ordered
the rig.
After being delivered by TNT-post, incl. 'operation manual 'I connected the Uniden 2030
to a simple GP antenna. After some CQ's on 145.500 MHz, PA65L from Leiden responded.
Everything worked fine !
No frequency synthesizers or PLL in this rig, but 12 discrete Xtal positions. That's how
it was done in the late 70's.
Crystal positions are as follows:
1) 145.250 MHz
2) -
3) 145.500 MHz
4)-
5)-
6) 145.400 MHz
7) 145.175 MHz
8) 145.000 MHz
9) 145.100 MHz
10) 145.050 MHz
11) 145.200 MHz
12) 145.075 MHz
The Uniden has a switch to set the output power; you can select 1 or 10 Watts.
The transistor producing 10 Watts is a 2SC1605A. An 'automatic protection circuit'
assures that the PA is switched off when the SWR becomes too high.
Trash (?)
Think twice before you throw away old consumer electronics. Often they contain a huge amount of nice components to add to your spare part stock.
This week I saved a printed circuit board from an old Samsung colour TV (over 10 years old with CRT). Some components to retrieve from this board:
Of course there is a VHF/UHF tuner. Nice part to make your own panorama receiver for example.
Furthermore lots of resistors also big ones (> 5 Watts).
About 10 chokes (coils), 4 xtals, voltage regulators (7805, 7809, 7812, 7915), lots of
capacitors in all kind of values (from 20 pF ... 220nF). electrolytic capacitors, heat sinks, on-off switch, variable resistors, Japanese transistors (common use and special transistors for video purposes).
I will not desolder the specialized video ICs and hi voltage transformer (which has collected lots of dust). I am sure I will never use these.
Who said our hobby is expensive ? All you need is there free for use :-) And the internet is your best friend when you want the details from an unknown object.
Friday, 9 August 2013
GHz frequency counter ready
Finally I am ready with the construction of the frequency counter. Found some time to integrate the pre-scaler, stick some labels on the front and assemble the housing. The counter has a BNC and SMA connector as entrance. As you might have read the housing comes from an old PC PSU which I painted gray (front) and black (top). First trials are succesfull.
The final result looks as follows:
I found the counter is able to measure frequencies in the GHz range. The counter was tested with a QRP ATV transmitter and I saw that it indicated 1.257 GHz, exactly the working frequency of the transmitter.
The design of the pre-scaler can be found on my second posting on this blog. The picture above shows the prescaler with MB506 chip on the unetched pcb on the left hand side of the housing. The prescaler is built using the "dead-bug method".
The main design of this counter comes from India. Have a look here:
http://www.hamradio.in/circuits/freq_counter_lcd.php
The final result looks as follows:
I found the counter is able to measure frequencies in the GHz range. The counter was tested with a QRP ATV transmitter and I saw that it indicated 1.257 GHz, exactly the working frequency of the transmitter.
The design of the pre-scaler can be found on my second posting on this blog. The picture above shows the prescaler with MB506 chip on the unetched pcb on the left hand side of the housing. The prescaler is built using the "dead-bug method".
The main design of this counter comes from India. Have a look here:
http://www.hamradio.in/circuits/freq_counter_lcd.php
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