¿ªÔÆÌåÓý

ctrl + shift + ? for shortcuts
© 2025 Groups.io
  1. QRPLabs
  2. Messages
Expanded Topics Messages Polls
Date
Re: QSX

 

As I recall, my first QRP rig (other than my not-really-QRP 15W? Novice rig in 1954) was the CRK-10A, a 40M transceiver. I was amazed at what the receiver could pull in, and all for around $40 at the time. Later I built my Forty-9er which proved to me just how important frequency agility is when you're running QRP. I added a VFO and LCD display to the Forty-9er (March, 2016, QST) and that made all the difference.

Why QRP? I really don't know what it is that makes it actually exciting to me. With my 100W rig, other than rare DX in a pile up, even my crappy dipole can usually work 'em. With QRP, I honestly think it hones your operating skills a little in the process. After I got my General, I said I would never send another letter in Morse, yet here I am 60 years later and getting a real kick out of it. I have also discovered that my software background can actually augment my QRP experience, and I'm really enjoying that, too.

I don't really know why QRP appeals to me so much, but if you haven't tried it recently, give it a whirl. You might find it excites you, too.

Jack, W8TEE

On Saturday, April 6, 2019, 8:02:37 PM EDT, Bill Cromwell <wrcromwell@...> wrote:


Hi Joe,

My first response was about what QRP *is*. It's about reduced power at
the transmitter output and more recently folks think of 5 watts. It is
not about the physical size of the gear. Obviously it can be smaller.
You can't put 1500 pounds of baloney in a five pound sack but five
pounds does fit in the smaller sack. However unfair it may seem you can
also put 5 pounds of baloney in the 1500 pound sack:) The obvious
question is "why would you?".

The comments about my Matchboxes also address "use what you have". I
have those Matchboxes. I also have higher power radios (only up to 100
watts) but those are presently collecting dust and cobwebs on the shelf.
I have used the higher power transmitters at levels below 5 watts
output. I did it because it was what I had at the time and participated
in some QRP events that specified 5 watts or less. Of course it's not
efficient. The tube heaters in the DX-100 burn up more than the output
signal! At 4 watts out it is still QRP:)

I agree about suitable cores. I see varying and even contradictory
reports regarding what does and does not work well. Even the
polyvaricons seem to work well. I am considering a slightly larger unit
using air variables and maybe air core inductors. They will tolerate
higher voltages - period. I suppose that would be along the line of a
scaled down matchbox. Nah! I have been using the BLT for a couple of
days here and I am going with that general approach.

RG-174 is wonderful stuff for test leads. I use RG-58 for jumpers in the
shack and twin lead, Ladder line, or direct connect to the end of the
wire antenna. I currently have a long (70 foot) chunk of coax for
antenna feed and it is *killing* me. I need a little bit more hardware
that I will get tomorrow and change the antenna! It's going to rain
tomorrow. I will just have to get wet:)

73,

Bill? KU8H


On 4/6/19 6:46 PM, Joe Street wrote:
> It is pretty funny picturing those kilowatt capable match boxes on a
> picnic table beside a diminutive QRP xcvr.? But food for thought:? The
> QRO guys build those big clunky (but low loss) boxes and run ladder line
> because 1% loss when running legal limit is still 10's of watts burned
> up in heat somewhere and things will literally melt, otherwise those QRO
> types probably wouldn't care about losing 1% of their power or maybe
> even 10% if it didn't hurt anything, but something I've always
> considered is when you are starting out with a few precious watts you
> should be as concerned about loss as the QRO crowd, but how many
> examples do we see of equipment used for QRP that doesn't give much
> consideration to loss.? Tuners using those plastic "polyvaricon" AM
> tuning capacitors (with a Q factor of about 30! according to W7ZOI's
> tests) small transformer cores or cores of unsuitable permeability (the
> cores don't noticably heat up because the power is low) long lossy
> feedlines to save weight like RG-174, etc etc.? Maybe it's just my OCD
> but I think as QRP operators we should consider these anciliary parts of
> our station with the same care and concern for loss as the QRO folks.?
> So yeah get those Johnson matchboxes out and run some open wire line!
> Unless you are climbing a mountain, why not?
>
> Joe ve3vxo
>
> On Sat, Apr 6, 2019 at 12:26 PM Bill Cromwell <wrcromwell@...
> <mailto:wrcromwell@...>> wrote:
>
>? ? Hi R. Tyson,
>
>? ? I have a pair of Johnson Matchboxes. Those will handle QRP for sure. I
>? ? have used them at 5 watts and less many many times. They do not even
>? ? get
>? ? warm! <evil grin>
>
>? ? I also have the BLT that is built into my PFR-3 and I intend to build
>? ? some more of those. I believe that is what you are describing here.
>? ? Those Matchboxes are not so convenient for carrying them out to the
>? ? field. They look out of place on the desk too alongside those small,
>? ? low
>? ? power radios. But still very effective. We don't really need a "kit" to
>? ? build any of those but I am sure they are available if desired.
>
>? ? 73,
>
>? ? Bill? KU8H
>
>? ? On 4/6/19 11:13 AM, R. Tyson via Groups.Io wrote:
>? ? ? > Antenna, ATU, SWR meter, dummy load ...? ?that's assuming you don't
>? ? ? > already have all of these.
>? ? ? > If you do have them - are they QRP versions ?
>? ? ? >
>? ? ? > I built a Z match ATU with a resistive bridge. That way the rig
>? ? always
>? ? ? > has a safe load while tuning for best SWR. A superbright LED
>? ? shows when
>? ? ? > the antenna is properly matched. The ATU is adjusted until the
>? ? LED goes
>? ? ? > out ,or failing that, until it goes a dim as you can get it.
>? ? ? >
>? ? ? > You get to match the antenna while protecting the PA transistors.
>? ? Once
>? ? ? > the antenna is matched then the resistive bridge is switched out
>? ? and the
>? ? ? > RF goes straight through without any loss.
>
>? ? --
>? ? bark less - wag more
>
>
>
>

--
bark less - wag more
Re: Qrp-labs and a Huff and Puff circuit board

 

Hi Joe,

If you are concerned about current drain, drift, AND phase noise you might consider a VXO. Obviously it won't tune from DC to daylight. So many choices, -sigh-

73,

Bill KU8H

On 4/6/19 7:03 PM, Joe Street wrote:
Hi Allison
All good points, however consider in the context, this is a PTO I am building for my Norcal 2030, a rig which has phenomenal dynamic range and large close in signal handling while sipping only 11mA of current from 12 volts!? Such an energy efficient design with such stellar performance begs to be taken out on field day, maybe somewhere far away where weight and battery life are important.? I wouldn't want to ruin the power efficiency with any kind of synth.? Also the phase noise of the PTO will be better than a synth and phase noise of the local oscillator is a factor in the large signal performance.? I'm trying to make this rig suitable for a changing temperature environment without ruining it.? I looked at fast huffnpuffs but fear these will have a negative affect on phase noise so I am now only considering the type that make a small correction no more frequently than a few times per second.? I hope I can make it work and not add more than a few mA to the overall current draw.? I will make it so it can be turned off as well if need be.
Joe ve3vxo
On Sat, Apr 6, 2019 at 6:23 PM ajparent1/KB1GMX <kb1gmx@... <mailto:kb1gmx@...>> wrote:
Generally with PTO radios of the tentec and Drake realm if the PTO
is drifting something
isn't right.? I start there.
Exceptions are Swan and Atlas plus a few older Tentec like the
Argonaut 505 and 509 as
they use a fairly high frequency PTO for some bands.? It doesn't
solve the problem of
dial calibration or drifting for narrow modes like JT8 or even PSK31.
Rather than going the huff&puff I just drop in a DDS or 5351 and
kill the problem cold.
The only one I've resorted to for that is one junker level Atlas 210
and that vfo was
not savable due to 11M mods the rig was subjected to.
Allison
--
bark less - wag more
Re: QSX

 

Hi Joe,

My first response was about what QRP *is*. It's about reduced power at the transmitter output and more recently folks think of 5 watts. It is not about the physical size of the gear. Obviously it can be smaller. You can't put 1500 pounds of baloney in a five pound sack but five pounds does fit in the smaller sack. However unfair it may seem you can also put 5 pounds of baloney in the 1500 pound sack:) The obvious question is "why would you?".

The comments about my Matchboxes also address "use what you have". I have those Matchboxes. I also have higher power radios (only up to 100 watts) but those are presently collecting dust and cobwebs on the shelf. I have used the higher power transmitters at levels below 5 watts output. I did it because it was what I had at the time and participated in some QRP events that specified 5 watts or less. Of course it's not efficient. The tube heaters in the DX-100 burn up more than the output signal! At 4 watts out it is still QRP:)

I agree about suitable cores. I see varying and even contradictory reports regarding what does and does not work well. Even the polyvaricons seem to work well. I am considering a slightly larger unit using air variables and maybe air core inductors. They will tolerate higher voltages - period. I suppose that would be along the line of a scaled down matchbox. Nah! I have been using the BLT for a couple of days here and I am going with that general approach.

RG-174 is wonderful stuff for test leads. I use RG-58 for jumpers in the shack and twin lead, Ladder line, or direct connect to the end of the wire antenna. I currently have a long (70 foot) chunk of coax for antenna feed and it is *killing* me. I need a little bit more hardware that I will get tomorrow and change the antenna! It's going to rain tomorrow. I will just have to get wet:)

73,

Bill KU8H

On 4/6/19 6:46 PM, Joe Street wrote:
It is pretty funny picturing those kilowatt capable match boxes on a picnic table beside a diminutive QRP xcvr.? But food for thought:? The QRO guys build those big clunky (but low loss) boxes and run ladder line because 1% loss when running legal limit is still 10's of watts burned up in heat somewhere and things will literally melt, otherwise those QRO types probably wouldn't care about losing 1% of their power or maybe even 10% if it didn't hurt anything, but something I've always considered is when you are starting out with a few precious watts you should be as concerned about loss as the QRO crowd, but how many examples do we see of equipment used for QRP that doesn't give much consideration to loss.? Tuners using those plastic "polyvaricon" AM tuning capacitors (with a Q factor of about 30! according to W7ZOI's tests) small transformer cores or cores of unsuitable permeability (the cores don't noticably heat up because the power is low) long lossy feedlines to save weight like RG-174, etc etc.? Maybe it's just my OCD but I think as QRP operators we should consider these anciliary parts of our station with the same care and concern for loss as the QRO folks. So yeah get those Johnson matchboxes out and run some open wire line! Unless you are climbing a mountain, why not?
Joe ve3vxo
On Sat, Apr 6, 2019 at 12:26 PM Bill Cromwell <wrcromwell@... <mailto:wrcromwell@...>> wrote:
Hi R. Tyson,
I have a pair of Johnson Matchboxes. Those will handle QRP for sure. I
have used them at 5 watts and less many many times. They do not even
get
warm! <evil grin>
I also have the BLT that is built into my PFR-3 and I intend to build
some more of those. I believe that is what you are describing here.
Those Matchboxes are not so convenient for carrying them out to the
field. They look out of place on the desk too alongside those small,
low
power radios. But still very effective. We don't really need a "kit" to
build any of those but I am sure they are available if desired.
73,
Bill? KU8H
On 4/6/19 11:13 AM, R. Tyson via Groups.Io wrote:
> Antenna, ATU, SWR meter, dummy load ...? ?that's assuming you don't
> already have all of these.
> If you do have them - are they QRP versions ?
>
> I built a Z match ATU with a resistive bridge. That way the rig
always
> has a safe load while tuning for best SWR. A superbright LED
shows when
> the antenna is properly matched. The ATU is adjusted until the
LED goes
> out ,or failing that, until it goes a dim as you can get it.
>
> You get to match the antenna while protecting the PA transistors.
Once
> the antenna is matched then the resistive bridge is switched out
and the
> RF goes straight through without any loss.
--
bark less - wag more
--
bark less - wag more
Re: LPF 20 Meters

 

Its not uncommon to see a 10% variation from one wound iron power core to
another.? Add to that even 10% caps and yes they can gang up on you.

My first test it to make sure the winding occupies 2/3 of the core or spread
them so it does then test. if not take off a winding or two.

The expected loss at 14.0 should be more like .5db but be sure you not
measuring a cable as well!? Its easy to get bitten by a cable or test setup.

Allison
Re: Qrp-labs and a Huff and Puff circuit board

 

Hi Allison

All good points, however consider in the context, this is a PTO I am building for my Norcal 2030, a rig which has phenomenal dynamic range and large close in signal handling while sipping only 11mA of current from 12 volts!? Such an energy efficient design with such stellar performance begs to be taken out on field day, maybe somewhere far away where weight and battery life are important.? I wouldn't want to ruin the power efficiency with any kind of synth.? Also the phase noise of the PTO will be better than a synth and phase noise of the local oscillator is a factor in the large signal performance.? I'm trying to make this rig suitable for a changing temperature environment without ruining it.? I looked at fast huffnpuffs but fear these will have a negative affect on phase noise so I am now only considering the type that make a small correction no more frequently than a few times per second.? I hope I can make it work and not add more than a few mA to the overall current draw.? I will make it so it can be turned off as well if need be.

Joe ve3vxo


On Sat, Apr 6, 2019 at 6:23 PM ajparent1/KB1GMX <kb1gmx@...> wrote:
Generally with PTO radios of the tentec and Drake realm if the PTO is drifting something
isn't right.? I start there.? ?

Exceptions are Swan and Atlas plus a few older Tentec like the Argonaut 505 and 509 as?
they use a fairly high frequency PTO for some bands.? It doesn't solve the problem of
dial calibration or drifting for narrow modes like JT8 or even PSK31.

Rather than going the huff&puff I just drop in a DDS or 5351 and kill the problem cold.
The only one I've resorted to for that is one junker level Atlas 210 and that vfo was
not savable due to 11M mods the rig was subjected to.

Allison

Re: QSX

 

It is pretty funny picturing those kilowatt capable match boxes on a picnic table beside a diminutive QRP xcvr.? But food for thought:? The QRO guys build those big clunky (but low loss) boxes and run ladder line because 1% loss when running legal limit is still 10's of watts burned up in heat somewhere and things will literally melt, otherwise those QRO types probably wouldn't care about losing 1% of their power or maybe even 10% if it didn't hurt anything, but something I've always considered is when you are starting out with a few precious watts you should be as concerned about loss as the QRO crowd, but how many examples do we see of equipment used for QRP that doesn't give much consideration to loss.? Tuners using those plastic "polyvaricon" AM tuning capacitors (with a Q factor of about 30! according to W7ZOI's tests) small transformer cores or cores of unsuitable permeability (the cores don't noticably heat up because the power is low) long lossy feedlines to save weight like RG-174, etc etc.? Maybe it's just my OCD but I think as QRP operators we should consider these anciliary parts of our station with the same care and concern for loss as the QRO folks.? So yeah get those Johnson matchboxes out and run some open wire line! Unless you are climbing a mountain, why not?

Joe ve3vxo


On Sat, Apr 6, 2019 at 12:26 PM Bill Cromwell <wrcromwell@...> wrote:
Hi R. Tyson,

I have a pair of Johnson Matchboxes. Those will handle QRP for sure. I
have used them at 5 watts and less many many times. They do not even get
warm! <evil grin>

I also have the BLT that is built into my PFR-3 and I intend to build
some more of those. I believe that is what you are describing here.
Those Matchboxes are not so convenient for carrying them out to the
field. They look out of place on the desk too alongside those small, low
power radios. But still very effective. We don't really need a "kit" to
build any of those but I am sure they are available if desired.

73,

Bill? KU8H

On 4/6/19 11:13 AM, R. Tyson via Groups.Io wrote:
> Antenna, ATU, SWR meter, dummy load ...? ?that's assuming you don't
> already have all of these.
> If you do have them - are they QRP versions ?
>
> I built a Z match ATU with a resistive bridge. That way the rig always
> has a safe load while tuning for best SWR. A superbright LED shows when
> the antenna is properly matched. The ATU is adjusted until the LED goes
> out ,or failing that, until it goes a dim as you can get it.
>
> You get to match the antenna while protecting the PA transistors. Once
> the antenna is matched then the resistive bridge is switched out and the
> RF goes straight through without any loss.

--
bark less - wag more
Re: Qrp-labs and a Huff and Puff circuit board

 

Generally with PTO radios of the tentec and Drake realm if the PTO is drifting something
isn't right.? I start there.? ?

Exceptions are Swan and Atlas plus a few older Tentec like the Argonaut 505 and 509 as?
they use a fairly high frequency PTO for some bands.? It doesn't solve the problem of
dial calibration or drifting for narrow modes like JT8 or even PSK31.

Rather than going the huff&puff I just drop in a DDS or 5351 and kill the problem cold.
The only one I've resorted to for that is one junker level Atlas 210 and that vfo was
not savable due to 11M mods the rig was subjected to.

Allison
Re: LPF 20 Meters

 

On Sat, Apr 6, 2019 at 09:02 PM, N6WKZ wrote:
I just built and tested a 20 meter low pass filter.

My Rigol DSA 815 says that it's down 1.9 db @ 14.000 MHZ. Isn't that a little too soon? I would think that the roll-off should start after 15 MHZ or so. (?)
Hi Phil,

Yes, all discussed before, and the original design is a bit sharp anyway ;-)

The TL;DR? answer is to take 1 or 2 turns off each toroid, or try spreading the coils out a bit.

That's all you need to do, don't try getting conned into other stuff, just trust me.

- Andy -
LPF 20 Meters

 

Hello All!

I just built and tested a 20 meter low pass filter.

My Rigol DSA 815 says that it's down 1.9 db @ 14.000 MHZ. Isn't that a little too soon? I would think that the roll-off should start after 15 MHZ or so. (?)

73

Phil N6WKZ


---
This email has been checked for viruses by AVG.
Re: QSX

 

Hi George,

Several others have offered links to kits. You may have seen them shortly after you sent this message :) The advantage to kits over scratch building is having all the parts in one place at the same time instead of hunting them down one or two at a time. There may be a ready made, attractive box to install the kit in. I have learned to make my own in aluminum or steel with some plastic or wood trim. Not everybody can do that.

You also get a unit that other people have and is proven by others in actual use. If you hit a speed bump there are others to help you with problems. I really like my BLT and I can recommend the general idea to anybody. I mentioned that I am going to fabricate some more of them. Good luck with your quest.

As for kits, I have started buying some from Hans especially to get a board with SMD parts already soldered. I have soldered some successfully but still have low confidence in my ability to do that. The ones I did have two or three terminals and not multi-pin ICs.

73,

Bill KU8H

On 4/6/19 1:38 PM, George Blass via Groups.Io wrote:
Hi R. Tyson
Thanks for the suggestions !
The ATU sounds like a great project. ?Do you know if anyone offers a kit version of the one you described.
Thanks
George
--
bark less - wag more
Re: QSX

George Blass
 

Hi R. Tyson

Thanks for the suggestions !

The ATU sounds like a great project. ?Do you know if anyone offers a kit version of the one you described.?

Thanks

George
Re: QSX

 

Hi R. Tyson,

I have a pair of Johnson Matchboxes. Those will handle QRP for sure. I have used them at 5 watts and less many many times. They do not even get warm! <evil grin>

I also have the BLT that is built into my PFR-3 and I intend to build some more of those. I believe that is what you are describing here. Those Matchboxes are not so convenient for carrying them out to the field. They look out of place on the desk too alongside those small, low power radios. But still very effective. We don't really need a "kit" to build any of those but I am sure they are available if desired.

73,

Bill KU8H

On 4/6/19 11:13 AM, R. Tyson via Groups.Io wrote:
Antenna, ATU, SWR meter, dummy load ...? ?that's assuming you don't already have all of these.
If you do have them - are they QRP versions ?
I built a Z match ATU with a resistive bridge. That way the rig always has a safe load while tuning for best SWR. A superbright LED shows when the antenna is properly matched. The ATU is adjusted until the LED goes out ,or failing that, until it goes a dim as you can get it.
You get to match the antenna while protecting the PA transistors. Once the antenna is matched then the resistive bridge is switched out and the RF goes straight through without any loss.
--
bark less - wag more
Re: QSX - kits and accessory while you wait

Brien Pepperdine
 

¿ªÔÆÌåÓý

I would concur. Specifically on the Z match tuner... the Emtech ZM-2 tuner is one that offers good tuning for coax and twin lead, and has the built-in resistive bridge for finals protection while tuning into the unknown.

Also, there are tuners at QRP kits, under Antenna accessory kits. A few types for balanced line etc. I think mostly these include a resistive bridge as above, with LED indicator.

A nice QRP meter such as from OHR.. via?

Other meters suffice as well from other sources if you need something small-ish.? Such as from G QRP in Britain. So if you need something to build in the interim, order away. Good accessories for any QRP shack, especially if you are wanting something small for portable operation.?

Of course, if you are considering going portable and have not done it before..look into what you might want or be able to use for an antenna? What band... what supports it (a pole, tree, etc) so you can work that out and get together things such as perhaps a dual or triple band antenna and the associated loading coils/caps (such as the Joe Everhart solution for his almost daily portable operations outlined on QRP-L mail list).

GL and looking forward to a turn in the WX for all of us who are looking to get back outside.....

Brien VE3VAW


---------- Original Message ----------
From: "R. Tyson via Groups.Io" <tysons2@...>
Date: April 6, 2019 at 11:13 AM

Antenna, ATU, SWR meter, dummy load ...? ?that's assuming you don't already have all of these.
If you do have them - are they QRP versions ?

I built a Z match ATU with a resistive bridge. That way the rig always has a safe load while tuning for best SWR. A superbright LED shows when the antenna is properly matched. The ATU is adjusted until the LED goes out ,or failing that, until it goes a dim as you can get it.

You get to match the antenna while protecting the PA transistors. Once the antenna is matched then the resistive bridge is switched out and the RF goes straight through without any loss.


?
Re: QSX

 

Antenna, ATU, SWR meter, dummy load ...? ?that's assuming you don't already have all of these.
If you do have them - are they QRP versions ?

I built a Z match ATU with a resistive bridge. That way the rig always has a safe load while tuning for best SWR. A superbright LED shows when the antenna is properly matched. The ATU is adjusted until the LED goes out ,or failing that, until it goes a dim as you can get it.

You get to match the antenna while protecting the PA transistors. Once the antenna is matched then the resistive bridge is switched out and the RF goes straight through without any loss.
Re: QSX

 

The 10W PA.? The QSX will be available with and without the PA for those that built it earlier.
Re: QSX

 

20 watt dummy load kit?
QSX

George Blass
 

Hi All

As I patiently for the release of the QSX is there anything I can start building?

Thanks
George
Re: Programming a fresh QCX CPU #qcx #firmware

 

Wes,

This thread was started to look for an alternative method of replacement for a dead uP in my QCX.? As in an alternative to setting around wondering if "Heck" will freeze over before a replacement arrives from Turkey.

73 Jack KZ5A
Re: Programming a fresh QCX CPU #qcx #firmware

 

OK2BQN,
The key in your method is "original microprocessor". Would you not need to have a functioning original uP to get it to give up the code? This thread was about how to handle a non-functioning uP, which would leave one stuck. No?
--
> I finally got it all together...now I can't remember where I put it<

VY 73,
Wes

AE6ZM

Sierra Vista, AZ

?
Re: #antenna #qcx #antenna #qcx

 

It would depend on what you wanted to aspect you were wanting to tune- min SWR or Max signal. If you had a good stable signal source to listen to on the QCX, you might find the S-meter would respond as you trimmed the antenna. But, that might not give you min SWR. Assuming you use 50 ohm feedline, the SWR presented to the QCX output stage is a function of the impedance of the antenna, and at resonance a dipole may not be 50 ohms, depending on height, etc. So, short answer would be- No, S meter will not be too useful to tune antenna to min SWR.
--
> I finally got it all together...now I can't remember where I put it<

VY 73,
Wes

AE6ZM

Sierra Vista, AZ

?
110681 - 110700 of 143507