New QRSS beacon G1IVG in IO92NL
Hi all,
Just to let you all know I have built my 30m QRSS beacon kit (Hans Summers Kit) and it should be on 10.140085 more or less. It's only on 100mw as far as I know and I'm inteested if anyone can RX me. I have put the TX directly at the feed point of a 1/2 wave 30m dipole in the loft and run the kit from a 5.2vdc PSU.
73 de Colin G1IVG (Market Harborough, Leicestershire, England)
www.g1ivg.com
|
Are you guys going to be at FDIM 2011 with a receiver kit? I want to be first in line to buy one :-)
Mike
WE0H
|
Re: The G0UPL/G0XAR shop is open again
Hi,
I have another 100 kits to pack this week......so stock levels should be back to normal soon..
Steve
On 28 February 2011 04:19, zl1ujg <zl1ujg@...> wrote:
?
Hi
After seeing the shop open again over the weekend, I talked to some other amateurs about some more purchases today, but returning from work, I notice its almost sold out again.
Is it going to be restocked soon or will it be a while before restocking?
Thanks
ZL1UJG
-- It is vain to do with more that which can be done with less.
|
Re: The G0UPL/G0XAR shop is open again
Hi
After seeing the shop open again over the weekend, I talked to some other amateurs about some more purchases today, but returning from work, I notice its almost sold out again.
Is it going to be restocked soon or will it be a while before restocking?
Thanks
ZL1UJG
|
Re: 30m QRSS beacon kit FSK setting / testing
Hi Dan
Driving the frequency shift with the tone test output is not a good idea in my opinion. Yes it will *look* like it is working Ok, but in fact what you are actually doing is then producing sidebands at 750Hz (or thereabouts). You'll be producing one FSK trace at your wanted frequency, and two unwanted FSK traces on either side 750 Hz away. That 750Hz will also be varying because it's only based on the AVR's internal RC oscillator so it will drift etc.
You'll be wasting a lot of power in those sidebands and potentially interfering with people up there (and down there). Somebody might be able to tell us relatively on a theoretical basis, how much power will be in your wanted signal compared to your two unwanted ones.
Basically in my opinion I believe it would be much better to find out why the voltage at pin 3 is only 0 - 0.9V and fix the root cause of the issue. Possibly a defective chip! If there is nothing at all connected to the pin, does it still produce only 0 - 0.9V? (Actually even 0.9V of shift would be enough to get 5Hz of FSK, it would just need a bigger coupling capacitor i.e. longer gimmick capacitor).
If you have a high resolution photograph of both sides of your PCB, I'd love to take a look at it, it might help me to make further suggestions.
73 Hans G0UPL
toggle quoted message
Show quoted text
--- In QRPLabs@..., Daniel Wiering <daniel.wiering@...> wrote:
Hi All,
My beacon is on the air now it is transmitting VK5DJW on 6s slow
The issue was the output form pin 3 of the chip, I was only getting
something like 0.-0.9v out for freq shift, so i used the tone test output
and the waveform in Argo seems to be fine, let me know if you see the beacon
Thanks for all the help
-Dan
VK5DJW
On Mon, Feb 21, 2011 at 7:13 PM, Stephen Farthing <squirrox@...>wrote:
Hi Dan,
Sorry to hear you are having trouble. I have copied this to Hans who
designed the beacon - he is extremely busy at the moment and may not have
time to reply. So consider my words a temporary measure until he gets back
to you.
1. The LED does not light when the beacon is operating. It is used as a
variable capacitance diode rather than an LED - this is a feature documented
on Hans's site. An LED costs a fraction of the amount of a "proper" varactor
which is why we use them it the kits.
2. The circuit diagram and the PCB silkscreen are correct. If you look at
the silk screen you will see a D shape where the LED fits. When you fit the
LED the flat side of the LED (which indicates the cathode) must correspond
with the flat on the silkscreen. As shown in the circuit diagram, the
cathode connects to the junction of R1 and C3. Loads of people have fitted
the LED the wrong way around....me included!
5. The gimmick capacitor at C3 adjusts the height of the signal. On my 40
meter beacon the wire length is 1.5 cm for each lead and 2 loose turns at
the base....this gives me a 4 Hz shift. Your mileage may vary.
3. As you can hear the output on your RX you would appear to be getting
power out. So I am guessing the issue really is with your ARGO setup. Take a
look at this excellent guide, by VK6DI,
<>
to setting up Argo...
Hope this helps,
72 de Steve G0XAR
On 21 February 2011 04:12, danw1million <daniel.wiering@...> wrote:
Hi all,
I was hoping someone could give me some advice on the setup for the 30m
QRSS beacon kit.
I have built the kit set it to 10.14050 MHz.
I tuned for max signal on CW/USB using a Yaesu receiver, and I also tried
tuning to 10.14050 using my IC7000 as a receiver and I get a series of
straight lines using argo but no keying waveform.
I can hear the keyer output from the chip working well using a bud
earphone, however I cannot see it in argo.
Things I have tried so far:
- I have tried the Led both ways as the pcb overlay did not match the
circuit diagram.
- I have tried changing the gimmick capacitor height from approx 15mm all
the way to nearly 50mm with loose and tight twisting.
- I have added a 6V regulator to the board so the freq does not drift as
much with voltage.
- I have tried CW receiver settings with different filters and also USB,
LSB, etc. but not luck
I have not yet tried:
- Earthing all unused jumper pins
- Isolated audio input to my receiver as currently it works with WSPR
What I would like to know is,
- should the led light up with keying at all ?
- is USB the correct receive mode ?
Any advice on this would be appreciated
I feel like there is something silly I am missing with this as
The signal from this little baby is nice and strong, the sine wave is
clean. I just want to get it keying on the air :)
-Dan
--
It is vain to do with more that which can be done with less.
|
Re: 30m QRSS beacon kit FSK setting / testing
Hi All,
My beacon is on the air now it is transmitting VK5DJW on 6s slow
The issue was the output form pin 3 of the chip, I was only getting something like 0.-0.9v out for freq shift, so i used the tone test output and the waveform in Argo seems to be fine, let me know if you see the beacon
Thanks for all the help
-Dan
VK5DJW
toggle quoted message
Show quoted text
On Mon, Feb 21, 2011 at 7:13 PM, Stephen Farthing <squirrox@...> wrote:
?
Hi Dan,
Sorry to hear you are having trouble. I have copied this to Hans who designed the beacon - he is extremely busy at the moment and may not have time to reply. So consider my words a temporary measure until he gets back to you.
1. The LED does not light when the beacon is operating. It is used as a variable capacitance diode rather than an LED - this is a feature documented on Hans's site. An LED costs a fraction of the amount of a "proper" varactor which is why we use them it the kits.?
2. The circuit diagram and the PCB silkscreen are correct. If you look at the silk screen you will see a D shape where the LED fits. When you fit the LED the flat side of the LED (which indicates the cathode) must correspond with the flat on the silkscreen. As shown in the circuit diagram, the cathode connects to the junction of R1 ?and C3. Loads of people have fitted the LED the wrong way around....me included!
5. The gimmick capacitor at C3 adjusts the height of the signal. On my 40 meter beacon the wire length is 1.5 cm for each lead and 2 loose turns at the base....this gives me a 4 Hz shift. Your mileage may vary.?
3. As you can hear the output on your RX you would appear to be getting power out. So I am guessing the issue really is with your ARGO setup. Take a look at this excellent guide, by VK6DI,?
to setting up Argo...
Hope this helps,
72 de Steve G0XAR
On 21 February 2011 04:12, danw1million <daniel.wiering@...> wrote:
?
Hi all,
I was hoping someone could give me some advice on the setup for the 30m QRSS beacon kit.
I have built the kit set it to 10.14050 MHz.
I tuned for max signal on CW/USB using a Yaesu receiver, and I also tried tuning to 10.14050 using my IC7000 as a receiver and I get a series of straight lines using argo but no keying waveform.
I can hear the keyer output from the chip working well using a bud earphone, however I cannot see it in argo.
Things I have tried so far:
- I have tried the Led both ways as the pcb overlay did not match the circuit diagram.
- I have tried changing the gimmick capacitor height from approx 15mm all the way to nearly 50mm with loose and tight twisting.
- I have added a 6V regulator to the board so the freq does not drift as much with voltage.
- I have tried CW receiver settings with different filters and also USB, LSB, etc. but not luck
I have not yet tried:
- Earthing all unused jumper pins
- Isolated audio input to my receiver as currently it works with WSPR
What I would like to know is,
- should the led light up with keying at all ?
- is USB the correct receive mode ?
Any advice on this would be appreciated
I feel like there is something silly I am missing with this as
The signal from this little baby is nice and strong, the sine wave is clean. I just want to get it keying on the air :)
-Dan
-- It is vain to do with more that which can be done with less.
|
Re: 30m QRSS beacon kit FSK setting / testing
Hi Arv K7HKL,
Thanks for the advice I will try that out tonight,
I have a couple of things to try now but I will add that to the list, I can definitely see the freq change when i touch parts near the oscillator section. However the QRSS kit is within 1 metre of the receiver..... so maybe i will move it more like 10 metres away and try again and retune :)
Thank you for your advice
-Dan
VK5DJW
toggle quoted message
Show quoted text
--- In QRPLabs@..., Arv Evans <arvid.evans@...> wrote:
Dan VK6DJW
Try touching the oscillator area while watching it on Argo. You should
be able to see it change frequency.
It is possible that you are watching some other signal resulting from
overload of your receiver. I had
similar problems until I added lots of attenuation on the receiver
antenna input and then could see the
QRSS transmitter at a more normal level (I was way off frequency!).
Arv K7HKL
On 02/21/2011 03:27 PM, Daniel Wiering wrote:
Hi Steve,
Thanks for your reply I appreciate the advice,
I returned the led to the correct way around and I have about 15-20mm
twisted tightly on the gimmick capacitor to try and get as much shift
as i can, i have a very strong signal in argo but no shift.
I am using a LM7806CV linear regulator soldered in to the pcb at the
power supply point on the board with 330uF on board with 220nF across
it and 82nF on the 6V output of the regulator.
I followed the excellent argo instructions by VK6DI and i have a
strong white line with a halo.
I did try using a 9V battery and it worked however with a lot of drift
as the battery discharged (battery was already low) I think the issue
could be the long lead from the pcb to the wall wart power supply or
something to do with the regulator being quite close by to the led and
the gimmick capacitor on the board. i think i will remove it and try
again... the poor little pcb is getting a thrashing with all the rework :)
Any one have any more tips for this issue ?
-Dan
VK5DJW
On Mon, Feb 21, 2011 at 7:13 PM, Stephen Farthing <squirrox@...
<mailto:squirrox@...>> wrote:
Hi Dan,
Sorry to hear you are having trouble. I have copied this to Hans
who designed the beacon - he is extremely busy at the moment and
may not have time to reply. So consider my words a temporary
measure until he gets back to you.
1. The LED does not light when the beacon is operating. It is used
as a variable capacitance diode rather than an LED - this is a
feature documented on Hans's site. An LED costs a fraction of the
amount of a "proper" varactor which is why we use them it the kits.
2. The circuit diagram and the PCB silkscreen are correct. If you
look at the silk screen you will see a D shape where the LED fits.
When you fit the LED the flat side of the LED (which indicates the
cathode) must correspond with the flat on the silkscreen. As shown
in the circuit diagram, the cathode connects to the junction of R1
and C3. Loads of people have fitted the LED the wrong way
around....me included!
5. The gimmick capacitor at C3 adjusts the height of the signal.
On my 40 meter beacon the wire length is 1.5 cm for each lead and
2 loose turns at the base....this gives me a 4 Hz shift. Your
mileage may vary.
3. As you can hear the output on your RX you would appear to be
getting power out. So I am guessing the issue really is with your
ARGO setup. Take a look at this excellent guide, by VK6DI,
<>
to setting up Argo...
Hope this helps,
72 de Steve G0XAR
On 21 February 2011 04:12, danw1million <daniel.wiering@...
<mailto:daniel.wiering@...>> wrote:
Hi all,
I was hoping someone could give me some advice on the setup
for the 30m QRSS beacon kit.
I have built the kit set it to 10.14050 MHz.
I tuned for max signal on CW/USB using a Yaesu receiver, and I
also tried tuning to 10.14050 using my IC7000 as a receiver
and I get a series of straight lines using argo but no keying
waveform.
I can hear the keyer output from the chip working well using a
bud earphone, however I cannot see it in argo.
Things I have tried so far:
- I have tried the Led both ways as the pcb overlay did not
match the circuit diagram.
- I have tried changing the gimmick capacitor height from
approx 15mm all the way to nearly 50mm with loose and tight
twisting.
- I have added a 6V regulator to the board so the freq does
not drift as much with voltage.
- I have tried CW receiver settings with different filters and
also USB, LSB, etc. but not luck
I have not yet tried:
- Earthing all unused jumper pins
- Isolated audio input to my receiver as currently it works
with WSPR
What I would like to know is,
- should the led light up with keying at all ?
- is USB the correct receive mode ?
Any advice on this would be appreciated
I feel like there is something silly I am missing with this as
The signal from this little baby is nice and strong, the sine
wave is clean. I just want to get it keying on the air :)
-Dan
--
It is vain to do with more that which can be done with less.
|
Re: 30m QRSS beacon kit FSK setting / testing
Dan VK6DJW
Try touching the oscillator area while watching it on Argo.??? You
should be able to see it change frequency.
It is possible that you are watching some other signal resulting
from overload of your receiver.??? I had
similar problems until I added lots of attenuation on the receiver
antenna input and then could see the
QRSS transmitter at a more normal level (I was way off frequency!).
Arv K7HKL
On 02/21/2011 03:27 PM, Daniel Wiering wrote:
toggle quoted message
Show quoted text
???
Hi Steve,
Thanks for your reply I appreciate the advice,
I returned the led to the correct way around and I have
about 15-20mm twisted tightly on the gimmick capacitor to
try and get as much shift as i can, i have a very strong
signal in argo but no shift.
I am using a LM7806CV linear regulator soldered in to the
pcb at the power supply point on the board with 330uF on
board with 220nF across it and 82nF on the 6V output of
the regulator.
I followed the excellent argo instructions by VK6DI and i
have a strong white line with a halo.
I did try using a 9V battery and it worked however with a
lot of drift as the battery discharged (battery was
already low) I think the issue could be the long lead from
the pcb to the wall wart power supply or something to do
with the regulator being quite close by to the led and the
gimmick capacitor on the board. i think i will remove it
and try again... the poor little pcb is getting a
thrashing with all the rework :)
Any one have any more tips for this issue ?
-Dan
VK5DJW
On Mon, Feb 21, 2011 at 7:13 PM,
Stephen Farthing <squirrox@...>
wrote:
???
Hi Dan,
Sorry to hear you are having trouble. I
have copied this to Hans who designed the
beacon - he is extremely busy at the moment
and may not have time to reply. So consider
my words a temporary measure until he gets
back to you.
1. The LED does not light when the beacon
is operating. It is used as a variable
capacitance diode rather than an LED - this
is a feature documented on Hans's site. An
LED costs a fraction of the amount of a
"proper" varactor which is why we use them
it the kits.???
2. The circuit diagram and the PCB
silkscreen are correct. If you look at the
silk screen you will see a D shape where the
LED fits. When you fit the LED the flat side
of the LED (which indicates the cathode)
must correspond with the flat on the
silkscreen. As shown in the circuit diagram,
the cathode connects to the junction of R1
???and C3. Loads of people have fitted the LED
the wrong way around....me included!
5. The gimmick capacitor at C3 adjusts
the height of the signal. On my 40 meter
beacon the wire length is 1.5 cm for each
lead and 2 loose turns at the base....this
gives me a 4 Hz shift. Your mileage may
vary.???
3. As you can hear the output on your RX
you would appear to be getting power out. So
I am guessing the issue really is with your
ARGO setup. Take a look at this excellent
guide, by VK6DI,???
to setting up Argo...
Hope this helps,
72 de Steve G0XAR
On 21 February
2011 04:12, danw1million <daniel.wiering@...>
wrote:
???
Hi all,
I was hoping someone could
give me some advice on the
setup for the 30m QRSS
beacon kit.
I have built the kit set it
to 10.14050 MHz.
I tuned for max signal on
CW/USB using a Yaesu
receiver, and I also tried
tuning to 10.14050 using my
IC7000 as a receiver and I
get a series of straight
lines using argo but no
keying waveform.
I can hear the keyer output
from the chip working well
using a bud earphone,
however I cannot see it in
argo.
Things I have tried so far:
- I have tried the Led both
ways as the pcb overlay did
not match the circuit
diagram.
- I have tried changing the
gimmick capacitor height
from approx 15mm all the way
to nearly 50mm with loose
and tight twisting.
- I have added a 6V
regulator to the board so
the freq does not drift as
much with voltage.
- I have tried CW receiver
settings with different
filters and also USB, LSB,
etc. but not luck
I have not yet tried:
- Earthing all unused jumper
pins
- Isolated audio input to my
receiver as currently it
works with WSPR
What I would like to know
is,
- should the led light up
with keying at all ?
- is USB the correct receive
mode ?
Any advice on this would be
appreciated
I feel like there is
something silly I am missing
with this as
The signal from this little
baby is nice and strong, the
sine wave is clean. I just
want to get it keying on the
air :)
-Dan
--
It is vain to do with more that which can be
done with less.
|
Re: 30m QRSS beacon kit FSK setting / testing
Hi Steve, Thanks for your reply I appreciate the advice,
I returned the led to the correct way around and I have about 15-20mm twisted tightly on the gimmick capacitor to try and get as much shift as i can, i have a very strong signal in argo but no shift.
I am using a LM7806CV linear regulator soldered in to the pcb at the power supply point on the board with 330uF on board with 220nF across it and 82nF on the 6V output of the regulator.
I followed the excellent argo instructions by VK6DI and i have a strong white line with a halo.
I did try using a 9V battery and it worked however with a lot of drift as the battery discharged (battery was already low) I think the issue could be the long lead from the pcb to the wall wart power supply or something to do with the regulator being quite close by to the led and the gimmick capacitor on the board. i think i will remove it and try again... the poor little pcb is getting a thrashing with all the rework :)
Any one have any more tips for this issue ?
-Dan
VK5DJW
On Mon, Feb 21, 2011 at 7:13 PM, Stephen Farthing <squirrox@...> wrote:
?
Hi Dan,
Sorry to hear you are having trouble. I have copied this to Hans who designed the beacon - he is extremely busy at the moment and may not have time to reply. So consider my words a temporary measure until he gets back to you.
1. The LED does not light when the beacon is operating. It is used as a variable capacitance diode rather than an LED - this is a feature documented on Hans's site. An LED costs a fraction of the amount of a "proper" varactor which is why we use them it the kits.?
2. The circuit diagram and the PCB silkscreen are correct. If you look at the silk screen you will see a D shape where the LED fits. When you fit the LED the flat side of the LED (which indicates the cathode) must correspond with the flat on the silkscreen. As shown in the circuit diagram, the cathode connects to the junction of R1 ?and C3. Loads of people have fitted the LED the wrong way around....me included!
5. The gimmick capacitor at C3 adjusts the height of the signal. On my 40 meter beacon the wire length is 1.5 cm for each lead and 2 loose turns at the base....this gives me a 4 Hz shift. Your mileage may vary.?
3. As you can hear the output on your RX you would appear to be getting power out. So I am guessing the issue really is with your ARGO setup. Take a look at this excellent guide, by VK6DI,?
to setting up Argo...
Hope this helps,
72 de Steve G0XAR
On 21 February 2011 04:12, danw1million <daniel.wiering@...> wrote:
?
Hi all,
I was hoping someone could give me some advice on the setup for the 30m QRSS beacon kit.
I have built the kit set it to 10.14050 MHz.
I tuned for max signal on CW/USB using a Yaesu receiver, and I also tried tuning to 10.14050 using my IC7000 as a receiver and I get a series of straight lines using argo but no keying waveform.
I can hear the keyer output from the chip working well using a bud earphone, however I cannot see it in argo.
Things I have tried so far:
- I have tried the Led both ways as the pcb overlay did not match the circuit diagram.
- I have tried changing the gimmick capacitor height from approx 15mm all the way to nearly 50mm with loose and tight twisting.
- I have added a 6V regulator to the board so the freq does not drift as much with voltage.
- I have tried CW receiver settings with different filters and also USB, LSB, etc. but not luck
I have not yet tried:
- Earthing all unused jumper pins
- Isolated audio input to my receiver as currently it works with WSPR
What I would like to know is,
- should the led light up with keying at all ?
- is USB the correct receive mode ?
Any advice on this would be appreciated
I feel like there is something silly I am missing with this as
The signal from this little baby is nice and strong, the sine wave is clean. I just want to get it keying on the air :)
-Dan
-- It is vain to do with more that which can be done with less.
|
The G0UPL/G0XAR shop is open again
Hi Guys,
The shop is back open.....I have another batch of 100 beacon PCBs to kit. I'll be ordering more crystals and toroids...
72/3 de Steve G0XAR
--
It is vain to do with more that which can be done with less.
|
Re: 30m QRSS beacon kit FSK setting / testing
Hi Dan,
Sorry to hear you are having trouble. I have copied this to Hans who designed the beacon - he is extremely busy at the moment and may not have time to reply. So consider my words a temporary measure until he gets back to you.
1. The LED does not light when the beacon is operating. It is used as a variable capacitance diode rather than an LED - this is a feature documented on Hans's site. An LED costs a fraction of the amount of a "proper" varactor which is why we use them it the kits.?
2. The circuit diagram and the PCB silkscreen are correct. If you look at the silk screen you will see a D shape where the LED fits. When you fit the LED the flat side of the LED (which indicates the cathode) must correspond with the flat on the silkscreen. As shown in the circuit diagram, the cathode connects to the junction of R1 ?and C3. Loads of people have fitted the LED the wrong way around....me included!
5. The gimmick capacitor at C3 adjusts the height of the signal. On my 40 meter beacon the wire length is 1.5 cm for each lead and 2 loose turns at the base....this gives me a 4 Hz shift. Your mileage may vary.?
3. As you can hear the output on your RX you would appear to be getting power out. So I am guessing the issue really is with your ARGO setup. Take a look at this excellent guide, by VK6DI,?
to setting up Argo...
Hope this helps,
72 de Steve G0XAR
On 21 February 2011 04:12, danw1million <daniel.wiering@...> wrote:
?
Hi all,
I was hoping someone could give me some advice on the setup for the 30m QRSS beacon kit.
I have built the kit set it to 10.14050 MHz.
I tuned for max signal on CW/USB using a Yaesu receiver, and I also tried tuning to 10.14050 using my IC7000 as a receiver and I get a series of straight lines using argo but no keying waveform.
I can hear the keyer output from the chip working well using a bud earphone, however I cannot see it in argo.
Things I have tried so far:
- I have tried the Led both ways as the pcb overlay did not match the circuit diagram.
- I have tried changing the gimmick capacitor height from approx 15mm all the way to nearly 50mm with loose and tight twisting.
- I have added a 6V regulator to the board so the freq does not drift as much with voltage.
- I have tried CW receiver settings with different filters and also USB, LSB, etc. but not luck
I have not yet tried:
- Earthing all unused jumper pins
- Isolated audio input to my receiver as currently it works with WSPR
What I would like to know is,
- should the led light up with keying at all ?
- is USB the correct receive mode ?
Any advice on this would be appreciated
I feel like there is something silly I am missing with this as
The signal from this little baby is nice and strong, the sine wave is clean. I just want to get it keying on the air :)
-Dan
-- It is vain to do with more that which can be done with less.
|
30m QRSS beacon kit FSK setting / testing
Hi all,
I was hoping someone could give me some advice on the setup for the 30m QRSS beacon kit.
I have built the kit set it to 10.14050 MHz.
I tuned for max signal on CW/USB using a Yaesu receiver, and I also tried tuning to 10.14050 using my IC7000 as a receiver and I get a series of straight lines using argo but no keying waveform.
I can hear the keyer output from the chip working well using a bud earphone, however I cannot see it in argo.
Things I have tried so far:
- I have tried the Led both ways as the pcb overlay did not match the circuit diagram.
- I have tried changing the gimmick capacitor height from approx 15mm all the way to nearly 50mm with loose and tight twisting.
- I have added a 6V regulator to the board so the freq does not drift as much with voltage.
- I have tried CW receiver settings with different filters and also USB, LSB, etc. but not luck
I have not yet tried:
- Earthing all unused jumper pins
- Isolated audio input to my receiver as currently it works with WSPR
What I would like to know is,
- should the led light up with keying at all ?
- is USB the correct receive mode ?
Any advice on this would be appreciated
I feel like there is something silly I am missing with this as
The signal from this little baby is nice and strong, the sine wave is clean. I just want to get it keying on the air :)
-Dan
|
Hans Summers TX kit mod for 12v
Hi,
I completed a document about modifying the Hans Summers QRSS TX kit for 12V PA operation.
Thank you to Joachim PA1GSJ for hosting the document.
Kevin
ZL1UJG
|
Modifying the Tx when working with a 12 v PSU
Hi,
I suspect a few of us are running these TXers off a 12/13.8 V PSU and regulating the PCB down to 5v.
A week or so back I considered running just the PA off 12V. I think some have already tried running them off 9v. I dont know much of their success.
These are just some notes from my work on a 40m version
(1) Cut a track to seperate the 2N7000 supply leaving the 47nF joined
(2) The FET output would match better via a 200 ohm transformer rather than a choke when running a 12.5v supply. I used a 6 turn bifilar choke using the existing FT37-43 on the drain of the 2N7000. (A 9 turn choke for 80m should be ok) The tap goes to the 1nF capacitor feeding the LPF.
6 turns is adequate as the inductive reactance,since it is about 10x the load value
(3)An additional 47nF or 100nF needed for bypass on the 5v supply on the PCB as there was only one bypass capacitor fitted.
My previous measurements on my 30m unit gave about 23mA for the other stages with ~ 60mA for the final FET stage for about 100mW output.
With the mod's the unit gave
(1) ~ 350 mW for 60 mA PA current (pushing the boundary a little)
(2) ~ 280 mW for 50 mA PA current
(3) ~ 100 mW for 23 mA PA current
Total transmitter currents are about 23mA higher
With the improved match and 12.5v, the PA efficiency is around 50% vs 33% for the 5v setup. So 350 mW o/p is possible but rather caning the 2N7000 since there is no heatsink (2N7000 device disappation max is 400 mW. At ~ 50mA final current it should be reliable
I checked the CW keying, by disconnecting the bias pot from the 5V and got in excess of 35 dB backwave
A little PCB/Vero/ratsnest for a 78L05 regulator and bypass capacitors is required for feeding the other stages from the 12v
Very pleased with the improvement in power (about 5 dB or 3X).This should improve the QRSS signals from this part of the world.
Another station is looking at using the changes in his 80m Hans Summers kit just received
Kevin
ZL1UJG
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My 10.140 kit has not been on the air much due to antenna work that needs to be done. Instead I made some spectrum measurements.
Harmonic suppression seems really good.
But there are some spurious about 50 to 60 dB down. Most likely caused by the internal clock of the micro. I plan to add some more decoupling an see if that might help.
A screenshot is in my photo section.
Joop - PE1CQP
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Re: frequency adjust 40m beacon kit
Thanks Kevin
will try that - one or two turns either way made so little difference that I couldn't tell which way to go
Tim
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--- In QRPLabs@..., "zl1ujg" <zl1ujg@...> wrote:
Hi,
I reckon it could be worth trying a 20% reduction in turns, as a start.
Kevin
ZL1UJG
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Re: frequency adjust 40m beacon kit
Hi,
I reckon it could be worth trying a 20% reduction in turns, as a start.
Kevin
ZL1UJG
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frequency adjust 40m beacon kit
Guys
I've just completed the 40m kit and it is operating properly except that I cannot adjust the frequency enough to bring it to the correct frequency.
The closest I can get is 7000350. I've tried playing with the windings of L1, but have not had success there either.
Has anyone any suggestions as to how many turns to add/remove from L1 to bring the frequency up enough to tune.
Thanks
Tim
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Hi,
Verify the total DC Current. I remember about 85-90 mA from my unit when set at 100 mW output when it was in FSK CW mode (now CW).
Is your RF cable OK and correct impedance (75 ohms can throw a curved ball if you are not careful)
Check DC volts on stages etc/ Mine is run on 5V.
On another topic
When I modified my 30m TX to CW as on the Hans Summers site. the CW back wave was only 13 dB down and added a 56 pF to ground from FET gate which improved it down to 33 dB or so. (Other bands might require experimenting.Drive RF was driving the FET into Class C.
Kevin
ZL1UJG
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I built my first 30m beacon and it worked first time, but I have not been able to get the power out up to 100mW (20dBm). I only get about 54mW (17dBm) into a 50 ohm load. I measured this several ways and verified it.
So I built my second kit and I get he very same results. I think this verifies that I didn't make an error on the first one. I have verified the output filter with ELSIE and it agrees very well. The apparent problem is excessive loss in the LP filter, but I don't think that that is the case.
73,
Cash KD5SSJ
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