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Re: Beacon is running

Stephen Farthing
 

Guys,

FWIW the formula for calculating RF power into a 50 ohm load from the peak to peak voltage observed on a scope is :-

Power = 2.5 x (Peak to peak voltage squared) milliwatts

So if you have a peak to peak voltage 0f 5 volts :-

Power = 2..5 (5x5)

Power = 2.5 x 25

Power = 62.5 milliwatts

I am happy to post a graph of Power vs Peak to Peak voltage in the files section if it makes things simple for the numerically challenged..

72/3 de Steve G0XAR





On 4 October 2010 16:52, PaulG <pgerhardt@...> wrote:
?


Hans

Thanks for your comments. The beacon has been running for several days now and the final seems ok temp wise with the output at 5.08V. I used this table of RF volts into 50 ohms



to determine the approximate power output. I will have to find a real 50 or 51 ohm load resistor and measure it again.

One problem I am seeing is the keyer often 'locks' up after sending the call once or a few times. Once though it ran all nite and was still keying. I wonder if it is related to the supply ? I am using an old Heathkit Reg P/S IP-18 that seems stable and clean.


--- In QRPLabs@..., "hanssummers2000" wrote:
>
>
> Hi Paul
>
> Congrats on finishing the kit. Yes, the transistor can get a bit hot when tuned for maximum output and it is best to turn the trimmer pot a bit back towards the "cold" end (ground) to lower the output a bit and feel more comfortable.
>
> 5.08V p-p into 36 ohms is not 250mW according to my calcs, it's 90mW. I think you have missed a divide-by-2 somewhere.
>
> Another thing to bear in mind is that the output low pass filter is designed for 50 ohm termination, I'm not sure what would change if you use 36 ohms.
>
> 72/3 Hans G0UPL
>
>
> --- In QRPLabs@..., "PaulG" wrote:
> >
> > Got the kit running on the bench still on 12 wpm with 36 ohm dummy load I am getting 5.08V p to p output on the scope. This is somewhere around 250 mw and is set somewhat below max output as max output causes the transistor to run pretty warm. I also found out that you can reverse voltage the PIC enough to cause a 2nd degree burn on the finger and it still seems to be working. I am letting it run overnight or for a few days before I put the antenna on it. Before it started working I had a bad looking sine wave at very low level. Also the final was amplifying this spurious signal. After poking and prodding and reheating some connections it starting running properly.
> >
> > Pix of it on bench at
> >
>




--
It is vain to do with more that which can be done with less.
Re: Beacon is running

Arv Evans
 

¿ªÔÆÌåÓý

Hello

Seems that there is some confusion regarding how to measure RF power.
There are several voltage measurement methods, including:
  • Average voltage

  • RMS voltage

  • Peak volts

  • Peak-to-Peak volts.
The chart that Paul noted shows the first 3 measurements but doesn't show
power converted from peak-to-peak voltage as you would see with a full-wave
rectifier or on an oscilloscope display.? If using peak-to-peak voltages it seems
one would want to divide-by-two, then use the peak volts part of the chart.

Arv
_._


On 10/04/2010 09:52 AM, PaulG wrote:

?


Hans

Thanks for your comments. The beacon has been running for several days now and the final seems ok temp wise with the output at 5.08V. I used this table of RF volts into 50 ohms



to determine the approximate power output. I will have to find a real 50 or 51 ohm load resistor and measure it again.

One problem I am seeing is the keyer often 'locks' up after sending the call once or a few times. Once though it ran all nite and was still keying. I wonder if it is related to the supply ? I am using an old Heathkit Reg P/S IP-18 that seems stable and clean.

--- In QRPLabs@..., "hanssummers2000" wrote:
>
>
> Hi Paul
>
> Congrats on finishing the kit. Yes, the transistor can get a bit hot when tuned for maximum output and it is best to turn the trimmer pot a bit back towards the "cold" end (ground) to lower the output a bit and feel more comfortable.
>
> 5.08V p-p into 36 ohms is not 250mW according to my calcs, it's 90mW. I think you have missed a divide-by-2 somewhere.
>
> Another thing to bear in mind is that the output low pass filter is designed for 50 ohm termination, I'm not sure what would change if you use 36 ohms.
>
> 72/3 Hans G0UPL
>
>
> --- In QRPLabs@..., "PaulG" wrote:
> >
> > Got the kit running on the bench still on 12 wpm with 36 ohm dummy load I am getting 5.08V p to p output on the scope. This is somewhere around 250 mw and is set somewhat below max output as max output causes the transistor to run pretty warm. I also found out that you can reverse voltage the PIC enough to cause a 2nd degree burn on the finger and it still seems to be working. I am letting it run overnight or for a few days before I put the antenna on it. Before it started working I had a bad looking sine wave at very low level. Also the final was amplifying this spurious signal. After poking and prodding and reheating some connections it starting running properly.
> >
> > Pix of it on bench at
> >
>
Re: Beacon is running

"PaulG"
 

Hans

Thanks for your comments. The beacon has been running for several days now and the final seems ok temp wise with the output at 5.08V. I used this table of RF volts into 50 ohms



to determine the approximate power output. I will have to find a real 50 or 51 ohm load resistor and measure it again.

One problem I am seeing is the keyer often 'locks' up after sending the call once or a few times. Once though it ran all nite and was still keying. I wonder if it is related to the supply ? I am using an old Heathkit Reg P/S IP-18 that seems stable and clean.

--- In QRPLabs@..., "hanssummers2000" <hans.summers@...> wrote:


Hi Paul

Congrats on finishing the kit. Yes, the transistor can get a bit hot when tuned for maximum output and it is best to turn the trimmer pot a bit back towards the "cold" end (ground) to lower the output a bit and feel more comfortable.

5.08V p-p into 36 ohms is not 250mW according to my calcs, it's 90mW. I think you have missed a divide-by-2 somewhere.

Another thing to bear in mind is that the output low pass filter is designed for 50 ohm termination, I'm not sure what would change if you use 36 ohms.

72/3 Hans G0UPL


--- In QRPLabs@..., "PaulG" <pgerhardt@> wrote:

Got the kit running on the bench still on 12 wpm with 36 ohm dummy load I am getting 5.08V p to p output on the scope. This is somewhere around 250 mw and is set somewhat below max output as max output causes the transistor to run pretty warm. I also found out that you can reverse voltage the PIC enough to cause a 2nd degree burn on the finger and it still seems to be working. I am letting it run overnight or for a few days before I put the antenna on it. Before it started working I had a bad looking sine wave at very low level. Also the final was amplifying this spurious signal. After poking and prodding and reheating some connections it starting running properly.

Pix of it on bench at

Re: Beacon is running

"hanssummers2000"
 

Hi Paul

Congrats on finishing the kit. Yes, the transistor can get a bit hot when tuned for maximum output and it is best to turn the trimmer pot a bit back towards the "cold" end (ground) to lower the output a bit and feel more comfortable.

5.08V p-p into 36 ohms is not 250mW according to my calcs, it's 90mW. I think you have missed a divide-by-2 somewhere.

Another thing to bear in mind is that the output low pass filter is designed for 50 ohm termination, I'm not sure what would change if you use 36 ohms.

72/3 Hans G0UPL

--- In QRPLabs@..., "PaulG" <pgerhardt@...> wrote:

Got the kit running on the bench still on 12 wpm with 36 ohm dummy load I am getting 5.08V p to p output on the scope. This is somewhere around 250 mw and is set somewhat below max output as max output causes the transistor to run pretty warm. I also found out that you can reverse voltage the PIC enough to cause a 2nd degree burn on the finger and it still seems to be working. I am letting it run overnight or for a few days before I put the antenna on it. Before it started working I had a bad looking sine wave at very low level. Also the final was amplifying this spurious signal. After poking and prodding and reheating some connections it starting running properly.

Pix of it on bench at

Beacon is running

"PaulG"
 

Got the kit running on the bench still on 12 wpm with 36 ohm dummy load I am getting 5.08V p to p output on the scope. This is somewhere around 250 mw and is set somewhat below max output as max output causes the transistor to run pretty warm. I also found out that you can reverse voltage the PIC enough to cause a 2nd degree burn on the finger and it still seems to be working. I am letting it run overnight or for a few days before I put the antenna on it. Before it started working I had a bad looking sine wave at very low level. Also the final was amplifying this spurious signal. After poking and prodding and reheating some connections it starting running properly.

Pix of it on bench at

Rainy day kit building

"PaulG"
 

With the rain coming up the East Coast I broke out my QRSS Beacon kit and got it started. On step 4 of the build I see a signal on the scope but can't find it on the rx or counter. Seem to have a signal at both the osc and the buffer. Am winding the rest of the coils and will add the final soon.

Kit was picked up at FDIM. I can hear the low level tone at step 1 as well.

Finished an end fed tuner matcher by KI6J and I may try it out with the QRSS Beacon if I can get it running...

Paul K3PG
I Hab 2 Balloon Launch and Beacon

"Ken Evans"
 

Just a reminder that the Iowa High Altitude Balloon (iHAB) project will
launch their second balloon with QRP beacon on Saturday. This launch is
sponsored by QRP ARCI.

The launch is scheduled for October 2, 2010 at 14:00Z (9AM CDT) from the
Ottumwa Industrial Airport (OTM) IHCC North Campus Aviation Building.
Preflight will begin at 13:00Z (8AM CDT). Should weather prevent the launch,
the fall back date will be Saturday, October 9, 2010 at the same times.

The QRP Beacon (1.6 watts) will be on 14.059.0 MHz signing (the QRP ARCI
Club call sign) "K6JSS iHAB 2". Post your spots of the beacon online at
www.qrpspots.com

A certificate will be available to people who provide a reception report.
Reports and requests for certificates should be sent to balloon@..."

Please go to for more information on the flight and
special recognition for reception reports.


Ken Evans, W4DU
President QRP ARCI
Re: Just finished soldering...

"Brad WF7T"
 

Sage advice Yan, and I will investigate. I did stumble upon the WSPR info and it started my thought process. Thank you for the PowerSDR article...I will glean what I can and get this puppy on the air!

73 Brad WF7T
Nashville EM66

--- In QRPLabs@..., "Yannick" <yannick.devos@...> wrote:

Hi Brad,

The easiest : tune to WW-V on 10 MHz and 15MHz. You should have a sharp carrier and will be able to notice your VFO error on two points.
If you are not able to receive WW-V or WW-H, there is other reference signal other the world in Russia for example.
Broadcast signals can also be used but their accuracy is worst. Ok in many cases but perhaps not precise enough for QRSS.

Here some tips :
(for WSPR but Ok for Argo)
(for PowerSDR)

73,
Yan.
---
Yannick DEVOS - XV4TUJ
(Blog in french)
(web page in english)

--- In QRPLabs@..., "Brad WF7T" <brad.wf7t@> wrote:

Update: To clarify, I need to "calibrate" ARGO in order to understand where my signal is being transmitted. Any pointers will be appreciated! 73 Brad



--- In QRPLabs@..., "Brad WF7T" <brad.wf7t@> wrote:

...my version of the QRSS board for 30M. Nice quick build and after a little bit of fiddling with the gimmick capacitor I have a nice 5Hz shift as seen in Argo while transmitting through a dummy load.

Using an IC-7600 through an EDZ for my monitoring setup as I set my final frequency I can actually see my signal (success!) Having only a few minutes of experience with Argo, I am wondering where I want to my signal to show in order to be in that 10.140.00 through 10.140.10 window? Assume I tune my RX rig to 10.140.00 USB.

I do not have a frequency counter handy, so I need to set my final frequency using my rig. I am pretty sure I can get the signal right in there, just having brain problems and will appreciate any pointers on using a rig to adjust my final frequency.

73 Brad WF7T
Re: Just finished soldering...

"Yannick"
 

Hi Brad,

The easiest : tune to WW-V on 10 MHz and 15MHz. You should have a sharp carrier and will be able to notice your VFO error on two points.
If you are not able to receive WW-V or WW-H, there is other reference signal other the world in Russia for example.
Broadcast signals can also be used but their accuracy is worst. Ok in many cases but perhaps not precise enough for QRSS.

Here some tips :
(for WSPR but Ok for Argo)
(for PowerSDR)

73,
Yan.
---
Yannick DEVOS - XV4TUJ
(Blog in french)
(web page in english)

--- In QRPLabs@..., "Brad WF7T" <brad.wf7t@...> wrote:

Update: To clarify, I need to "calibrate" ARGO in order to understand where my signal is being transmitted. Any pointers will be appreciated! 73 Brad



--- In QRPLabs@..., "Brad WF7T" <brad.wf7t@> wrote:

...my version of the QRSS board for 30M. Nice quick build and after a little bit of fiddling with the gimmick capacitor I have a nice 5Hz shift as seen in Argo while transmitting through a dummy load.

Using an IC-7600 through an EDZ for my monitoring setup as I set my final frequency I can actually see my signal (success!) Having only a few minutes of experience with Argo, I am wondering where I want to my signal to show in order to be in that 10.140.00 through 10.140.10 window? Assume I tune my RX rig to 10.140.00 USB.

I do not have a frequency counter handy, so I need to set my final frequency using my rig. I am pretty sure I can get the signal right in there, just having brain problems and will appreciate any pointers on using a rig to adjust my final frequency.

73 Brad WF7T
Re: Just finished soldering...

"Brad WF7T"
 

Update: To clarify, I need to "calibrate" ARGO in order to understand where my signal is being transmitted. Any pointers will be appreciated! 73 Brad

--- In QRPLabs@..., "Brad WF7T" <brad.wf7t@...> wrote:

...my version of the QRSS board for 30M. Nice quick build and after a little bit of fiddling with the gimmick capacitor I have a nice 5Hz shift as seen in Argo while transmitting through a dummy load.

Using an IC-7600 through an EDZ for my monitoring setup as I set my final frequency I can actually see my signal (success!) Having only a few minutes of experience with Argo, I am wondering where I want to my signal to show in order to be in that 10.140.00 through 10.140.10 window? Assume I tune my RX rig to 10.140.00 USB.

I do not have a frequency counter handy, so I need to set my final frequency using my rig. I am pretty sure I can get the signal right in there, just having brain problems and will appreciate any pointers on using a rig to adjust my final frequency.

73 Brad WF7T
Just finished soldering...

"Brad WF7T"
 

...my version of the QRSS board for 30M. Nice quick build and after a little bit of fiddling with the gimmick capacitor I have a nice 5Hz shift as seen in Argo while transmitting through a dummy load.

Using an IC-7600 through an EDZ for my monitoring setup as I set my final frequency I can actually see my signal (success!) Having only a few minutes of experience with Argo, I am wondering where I want to my signal to show in order to be in that 10.140.00 through 10.140.10 window? Assume I tune my RX rig to 10.140.00 USB.

I do not have a frequency counter handy, so I need to set my final frequency using my rig. I am pretty sure I can get the signal right in there, just having brain problems and will appreciate any pointers on using a rig to adjust my final frequency.

73 Brad WF7T
QRP Labs online shop

"hanssummers2000"
 

All

I have the online shop up and running, please scroll down to the bottom of the left hand menu on my website home page or visit to see the shop directly. I've added a components section too where you can buy spare parts for the beacon kits (crystals, toroids, transistors, PCB's). I hope this helps.

73 Hans G0UPL
Re: 20m inductor values

"hanssummers2000"
 

Hi all

This may save you some time. The beacon design uses the standard harmonic
output filter designs used by the GQRP club documented here
. So a good starting point will be the one
for 20 meters. You might find that the 2n7000 will not put out much output
power at 20 Meters, but hey, this is QRSS and we dont need much output power
:-)...
Please note people, that you may also need to reduce the value of the capacitors in the base/emitter of the Colpitts oscillator. They are 220pF in the 30m version. I think for 20m I think I would be tempted to start with a first guess of 150pF and see if that worked.

73 Hans G0UPL
Re: 20m inductor values

Stephen Farthing
 

Guys,

This may save you some time. The beacon design uses the standard harmonic output filter designs used by the GQRP club documented here?. So a good starting point will be the one for 20 meters. You might find that the 2n7000 will not put out much output power at 20 Meters, but hey, this is QRSS and we dont need much output power :-)...

I hope to make a 20 meter version myself in the next week or so and will report back....

72/3 de Steve G0XAR

--
It is vain to do with more that which can be done with less.
Re: 20m inductor values

Arv Evans
 

¿ªÔÆÌåÓý

Chris KE9YK

Use the calculator located here
Select your core type, plug in the frequency and any one other
value and it will spit out the inductance, turns, capacitance, etc.

If duplicating the G0UPL design you can use that calculator to
determine the impedance of his coils, then plug that back in
for 20 meters and get the L, C, turns, etc. info very quickly.

Arv K7HKL
_._

On 09/17/2010 05:43 PM, Chris Lantaff wrote:

?

Has anyone worked out the inductor values for 20m.
I have a program somewhere but can't find it now that it's needed.
?
Thanks,
- Chris KE9YK
20m inductor values

"Chris Lantaff"
 

¿ªÔÆÌåÓý

Has anyone worked out the inductor values for 20m.
I have a program somewhere but can't find it now that it's needed.
?
Thanks,
- Chris KE9YK
Kit availability

"Stephen"
 

Hello everyone,

I am waiting for some toroids to arrive from the USA so that I can complete this run of kits. The 40 and 80 meter kits did not sell so well so I will be using what I have left for 30 meters when the toroids are here.

It looks like there is enough demand for a further run of kits so I will order up another 100 PCBs and components and should have the stock ready by the end of September. We will still have kits for 40 and 80 as well as the more popular 30 meters. Once I have replaced the antennas that blew down last week I hope to try out a prototype 20 meter version (Nick of Genesis radio gets thanks for providing some free Xtals for evaluation - if it was not for Nicks Xtals we probably would not be able to do the kits).

The boards for the first run of RX kits look good and Hans is working on finalizing component values. We will announce the kits when they are ready to send which should be the end of Sept, early Oct. Kits will be available for 30, 40 and 80 meters.

To streamline the order process and generally make my life simpler Hans is putting together an on line shop which will be how we will manage orders in future. I will also be taking kits to sell to the GQRP Club rally at Rishworth in Oct and the VERON Day of the Amateur rally at Appledorn Netherlands, in Nov.

Bye for now,

Steve G0XAR
Re: OT - Problems posting to Knightsqrss...

Stephen Farthing
 

IMHO the issue might be google. I have had a googlemail account for a few years, a couple of months ago google asked me to change from googlemail to gmail. I did this and whilst i still get googlemail emails i have had to alter my address with yahoo groups ect...so you may need to do the same,

regards, Steve

--
It is vain to do with more that which can be done with less.
Re: OT - Problems posting to Knightsqrss...

Mike-WE0H
 

The problem is Gmail. I found the same problem with not seeing my own posts on many Groups and email reflectors. The solution is to not use Gmail. That is why I setup a GMX mail account. Now I see all my own posts on all the reflectors & Groups I subscribe. Whatever Gmail is doing, it will not allow your post to come back to your email account. Strange.

Mike-WE0H
Re: OT - Problems posting to Knightsqrss...

colinjt@...
 

On Friday 27 August 2010 15:28:42 Bob wrote:
This is a little OT but since I can't post to Knightsqrss for an answer
and the list owner never replies, I'll try here. Messages I send never
seem to post. I enter the posting page at Knightsqrss@..., compose
message and send. I set acknowledge on and I get an acknowledgment that
the list server received my post but it never shows up. I've tried plain
text, no go. I use gmail......Any ideas? I'd like to show my
captures....Help... TNX...Bob...WA1EDJ...
Bob,

I saw your test post to the Knights mail list, maybe the default for the list
is to *not* see your own posts?

You can set this in the mailing list membership configuration page, just login
with your Email address and password provided.

73 Colin - G6AVK

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