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AA8KT
03-13-2014, 04:58 AM
I am just getting into homebrew qrp, my question is how to cq in cw. should I call "de aa8kt/qrp aa8kt/qrp or just aa8kt/qrp aa8kt aa8kt or just call aa8kt ? Tnx fer advice

Peter AA8KT

N8YX
03-13-2014, 05:28 AM
Peter,

Welcome to the Island!

When I work low-power CW I usually send a 3x1 CQ and append my call with a /QRP.

Better to get a lot of short CQs out there with a call when running low power than one long one which may or may not be subject to fading or QRN.

Of course, YMMV. ;)

AA8KT
03-13-2014, 11:43 AM
TNX. I like that better than what I suggested.

W9JEF
03-13-2014, 11:43 AM
.


I usually check into the Razorback Net
(3987.5, nightly at 6:30 pm central time zone)
with the Icom IC-706 cranked down to 5 watts.

On CW, I seek out weaker CQs in hope of working QRP stations.
But I mostly run barefoot (100 watts) for any stateside QSO.

If you're QRP, best keep your transmissions short,
so the other station can continue to hold the frequency.

Some say, that life is too short for QRP...
but the problem may likely be too short an antenna. ;)

AA8KT
03-13-2014, 12:23 PM
To amend the question, for qrp operators out there. I am getting a 40meter Pixie tranceiver with a CW decoder and will be running a longwire. Is there anything else I need to get on the air??

K7SGJ
03-13-2014, 12:31 PM
To amend the question, for qrp operators out there. I am getting a 40meter Pixie tranceiver with a CW decoder and will be running a longwire. Is there anything else I need to get on the air??

I'm assuming you have a key etc. You may want to think about a dipole or OCFD for the antenna since you are only using 40 meters. And, since you will be in the cw portion, an antenna tuner won't be necessary, as long as you "prune" the antenna to the right length. That way, you will have a better chance to maximize you signal by matching the antenna to the rig.

Whenever you are ready to get on the air for the first time to check out the station, make a post here. I'm sure several of us can be around to lend an ear to see if we can hear, and/or work you. Good luck with the project. Glad to see that cw is of interest to you.

AA8KT
03-13-2014, 12:35 PM
Thanks

KJ3N
03-13-2014, 12:42 PM
To amend the question, for qrp operators out there. I am getting a 40meter Pixie tranceiver with a CW decoder and will be running a longwire. Is there anything else I need to get on the air??

A long wire is typically defined as 1WL or more at the operating frequency. In this case, that's at least 130 feet. What will you use for a counterpoise? What tuner do you plan on using?


You may want to think about a dipole or OCFD for the antenna since you are only using 40 meters. And, since you will be in the cw portion, an antenna tuner won't be necessary, as long as you "prune" the antenna to the right length. That way, you will have a better chance to maximize you signal by matching the antenna to the rig.

This would be a better option.

K0RGR
03-13-2014, 01:28 PM
I'd nix the longwire in favor of a dipole or an end-fed 1/2 wave. http://www.parelectronics.com/end-fedz.php You can make your own end fed - there are designs on the web.

AA8KT
03-13-2014, 04:07 PM
I live in an apartment so I can't run a dipole outside but can hide a longwire in the trees, or I can tie into the rain gutter that goes around all 4 sides of the building.

K7SGJ
03-13-2014, 04:24 PM
I live in an apartment so I can't run a dipole outside but can hide a longwire in the trees, or I can tie into the rain gutter that goes around all 4 sides of the building.

Sometimes, living conditions dictate the use of a compromise antenna. Then for now, I'd recommend an antenna tuner to help you match the radio to what ever you end up with for an antenna. As they say, any antenna is better than none at all. There are all kinds of QRP antenna tuners and auto antenna tuners for QRP that would get the job done. Elecraft has their T1 20 watt ATU kit for $140, and you can find them used on QTH and other sites for less. Also you might want to google QRP antenna tuner as there are several clubs that offer kits, too. Or, you can always build up a manual tuner if you want to. But the bottom line is, with a random long wire, your best bet is to use a tuner with it. At QRP levels, every mw you can couple to the antenna is in your best interest.

Another thought comes to mind, too. If you plan on taking it out to the park or camping, etc., you might want to consider something like a buddy pole. I have one, and it is nice for remote ops. There are many different antenna styles like it that allow you to tune the antenna to the radio by moving a tap on a coil on the antenna. When you want to operate, just put it on your porch or balcony. There again, those can be found used, or there are a lot of plans on line that describe how to build one, and where to get any specialty parts you might need. It's just another possibility. That's the beauty of the hobby. Keep experimenting and improving the signal a little at a time. You even get to learn some neat stuff along the way.

Good luck.

W9JEF
03-14-2014, 09:44 AM
.


I once operated--quite successfully--from a 3rd-story apartment.

Ran a quarter-wave wire out a window, direct from the rig--no tuner.

To keep RF out of the shack (and for efficiency), you need a counterpoise
(RF ground):
Just run another quarter wave wire connected to the radio's chassis,
and as much as practical in the opposite direction of the other leg of your dipole.
Keep both wires in the clear as they both will radiate, and be hot at the ends.

Good luck--hope to see you on 40 CW, one of my favorite bands.

73,

Jim

kb2vxa
03-14-2014, 10:52 AM
Just my $2 (2c adjusted for inflation) for whatever it's worthless.

Since QRP means getting as much signal on the air as you can, and ATUs have loss, you should avoid using one if possible. That's why a dipole cut to 1/2 wave was suggested. Since you'll be using an end fed wire, 1/4 wave 33ft should be possible. Since it requires a ground counterpoise, connection to a cold water pipe if possible is recommended, second choice is another 33ft wire run around the shack tucked out of sight, it doesn't have to be straight. Avoid using the AC mains protective ground (screw holding the cover plate on a wall outlet) and/or 3 wire power cord on the power supply. If you're using one with a 3 prong plug you can isolate it from ground using a three prong adapter with the lug that goes under the wall plate screw cut off. Of course you can always use a battery and avoid all that. The whole point in avoiding AC mains ground is you don't want to feed RF, not even QRP into the wiring for reasons that should be obvious.

Re JEF:
"Just run another quarter wave wire connected to the radio's chassis,
and as much as practical in the opposite direction of the other leg of your dipole.
Keep both wires in the clear as they both will radiate, and be hot at the ends.

Not to be contradictory, but to clarify:
A wire connected to chassis ground does not half a dipole make, that's why my first choice is a cold water pipe. I believe what he meant to say is it's a ground counterpoise to the radiating element as I have stated above. It's not intended to radiate but it may somewhat, so you may get some RF in the shack, but with CW you don't have to worry about RF feedback getting into a microphone that doesn't exist. I wouldn't worry about other shack equipment either (too much stuff to get into here) with QRP CW, not enough RF to cause any "serious damage".

I hope you find this mess helpful, that's what we're here for. I look at one aspect of Amateur Radio this way, I was elmered, and now it's my turn to return the favor.

W9JEF
03-14-2014, 11:31 AM
<snip>

Re JEF:
"Just run another quarter wave wire connected to the radio's chassis,
and as much as practical in the opposite direction of the other leg of your dipole.
Keep both wires in the clear as they both will radiate, and be hot at the ends."

Not to be contradictory, but to clarify:
A wire connected to chassis ground does not half a dipole make, that's why my first choice is a cold water pipe. I believe what he meant to say is it's a ground counterpoise to the radiating element as I have stated above. It's not intended to radiate but it may somewhat, so you may get some RF in the shack, but with CW you don't have to worry about RF feedback getting into a microphone that doesn't exist. I wouldn't worry about other shack equipment either (too much stuff to get into here) with QRP CW, not enough RF to cause any "serious damage".

I hope you find this mess helpful, that's what we're here for. I look at one aspect of Amateur Radio this way, I was elmered, and now it's my turn to return the favor.

Picture a half-wave dipole fed with a coax feedline.
Now eliminate the feedline, and you still have the dipole,
the leg formerly connected to the coax shield,
now directly to chassis ground (the center of the dipole).

I have much the same configuration using my 80 meter turnstile
(2 crossed inverted vees, up about 48 feet),
its 4 legs in parallel as a quarter-wave cage umbrella vertical on 160.
It's fed against about 30 or so radials, AND the powerline neutral
(close to in-shack service entrance).

Each hot (120 volt) "phase" is bypassed with .01 @2500 v micas capacitors.
During the last CQ 160m SSB 'test, several stations commented on the "good signal." :)

A water pipe "ground" will have inductance
--it may not be a very good RF ground at all
(unless length is a half-wave multiple).

If any ground conductor is carrying RF current, it WILL RADIATE.
Whether or not your powerline ground is actually connected to your radio ground,
if it's in the near field, it WILL carry RF current, and WILL RADIATE.

You might experiment with various ground hookups
for best efficiency, and/or least RFI. :)

kb2vxa
03-14-2014, 06:02 PM
"A water pipe "ground" will have inductance
--it may not be a very good RF ground at all
(unless length is a half-wave multiple)."

That's what an "artificial ground" is for. http://www.mfjenterprises.com/Product.php?productid=MFJ-931

I did say "not to be contradictory" but you're looking for an argument. Bye bye.

K7SGJ
03-14-2014, 06:51 PM
I hope the OP isn't getting confused or discouraged. :headscratch:

K6BSO
03-14-2014, 07:18 PM
Grounding is not as big a deal as some folks make it out to be unless there's a thunderstorm happening in your immediate vicinity. Don't get me wrong, it's good engineering practice, but it seems like some hams make a hobby out of grounding itself.

W9JEF
03-14-2014, 08:46 PM
"A water pipe "ground" will have inductance
--it may not be a very good RF ground at all
(unless length is a half-wave multiple)."

That's what an "artificial ground" is for. http://www.mfjenterprises.com/Product.php?productid=MFJ-931

I did say "not to be contradictory" but you're looking for an argument. Bye bye.

I think we're actually talking about the same thing.

Feeding a single wire antenna, a counterpoise
can be considered an artificial "ground" (for RF).

Your ground stakes, water pipe, etc. are for safety. :)

kb2vxa
03-15-2014, 07:17 AM
"I hope the OP isn't getting confused or discouraged."
Yeah, me too. I have a feeling he'll sort this out since he's well on the way already. I'm just glad this didn't turn into one of those each trying to outscience the other threads, that would turn ANYBODY off.

"Grounding is not as big a deal as some folks make it out to be unless there's a thunderstorm happening in your immediate vicinity."
When it comes to "some folks" you ain't seen nuthin yet! There's another "over there" you haven't discovered, RadioReference dot com. It's the biggest scanner site as opposed to the biggest ham site, only between them asking stupid questions before thinking and coming up with the answers right in front of their faces, grounding and lightning protection is the most widely discussed, argumentative, and worst ball of confusion I've ever seen!

"I think we're actually talking about the same thing."
In one sense we are, a ground counterpoise or the Earth itself takes the place of the "other side" of a dipole in an unbalanced antenna system.

"Feeding a single wire antenna, a counterpoise
can be considered an artificial "ground" (for RF)."
You're confusing ground with artificial ground again. We know what ground is, but as I explained previously an artificial ground shifts the RF phase so the current point of the wave appears at the transmitter. When it's used with an actual ground it brings the earthing point to the transmitter as if it were sitting on the ground.

"Your ground stakes, water pipe, etc. are for safety."
That's one thing, the other is for RF grounding as outlined above.

I hope this settles things once and for all, any more is pointless discussion. We wouldn't need or use an artificial ground tuner nor would MFJ make one if they didn't have a purpose.

W9JEF
03-15-2014, 11:09 AM
"I hope the OP isn't getting confused or discouraged."
Yeah, me too. I have a feeling he'll sort this out since he's well on the way already. I'm just glad this didn't turn into one of those each trying to outscience the other threads, that would turn ANYBODY off.

"Grounding is not as big a deal as some folks make it out to be unless there's a thunderstorm happening in your immediate vicinity."
When it comes to "some folks" you ain't seen nuthin yet! There's another "over there" you haven't discovered, RadioReference dot com. It's the biggest scanner site as opposed to the biggest ham site, only between them asking stupid questions before thinking and coming up with the answers right in front of their faces, grounding and lightning protection is the most widely discussed, argumentative, and worst ball of confusion I've ever seen!

"I think we're actually talking about the same thing."
In one sense we are, a ground counterpoise or the Earth itself takes the place of the "other side" of a dipole in an unbalanced antenna system.

"Feeding a single wire antenna, a counterpoise
can be considered an artificial "ground" (for RF)."
You're confusing ground with artificial ground again. We know what ground is, but as I explained previously an artificial ground shifts the RF phase so the current point of the wave appears at the transmitter. When it's used with an actual ground it brings the earthing point to the transmitter as if it were sitting on the ground.

"Your ground stakes, water pipe, etc. are for safety."
That's one thing, the other is for RF grounding as outlined above.

I hope this settles things once and for all, any more is pointless discussion. We wouldn't need or use an artificial ground tuner nor would MFJ make one if they didn't have a purpose.


"MFJ-931 creates an artificial RF ground!
It resonates a random length of wire thrown along the floor
and produces a tuned counterpoise. This ground effectively
places your rig near actual earth ground potential
even if your rig is on the second floor or higher
with no earth ground possible."

Difference between a quarter-wave wire counterpoise and MJF's "tuned counterpoise"
--less loss with the full-size counterpoise. Not to mention the $109.95 you save. :)

kb2vxa
03-15-2014, 03:43 PM
Cherry picking is fun. On to the NEXT paragraph:
Also, the MFJ-931 electrically places a far away RF ground directly at your rig -- no matter how far away it is. It reduces the electrical length of the ground connection wire to virtually zero by tuning out its reactance.

"Not to mention the $109.95 you save."
Colyn Baillie-Searle GD4EIRP (Practical Wireless, October 1990) knows how to build one, do you? (;->)

W9JEF
03-16-2014, 11:38 AM
Nice fancy schematic of the actual circuitry for what the company literature says,

"MFJ-931 creates an artificial RF ground!
It resonates a random length of wire thrown along the floor
and produces a tuned counterpoise. This ground effectively
places your rig near actual earth ground potential
even if your rig is on the second floor or higher
with no earth ground possible."

The POINT: As many of us have done in the past,
why not just a resonant length of counterpoise wire,
and save yourself $109.95? :)


Colyn Baillie-Searle GD4EIRP (Practical Wireless, October 1990) knows how to build one, do you? (;->)

Yes, and I would have put the variable capacitor
--whose voltage rating would be much higher than the one shown--
on the low-Z side of the coil (rotor at the lowest potential).

kb2vxa
03-16-2014, 12:11 PM
You just don't give up do you? (;->) Never mind, if the poor guy isn't laughing his head off he's so confused he went over to QRZ for an answer, decided next time when he's finished with the Altoids he'll throw the tin in the garbage, or threw THIS one in the garbage and is banging his head on the wall. (;->)

W9JEF
03-17-2014, 07:49 AM
You just don't give up do you? (;->) Never mind, if the poor guy isn't laughing his head off he's so confused he went over to QRZ for an answer, decided next time when he's finished with the Altoids he'll throw the tin in the garbage, or threw THIS one in the garbage and is banging his head on the wall. (;->)

Or perhaps he's now hip to the obvious, sensible, and economic way
to eliminate RF in the shack, and lays down a resonant counterpoise,
saving himself $109.95 (plus shipping). :)

kom
03-19-2014, 04:23 PM
I am just getting into homebrew qrp, my question is how to cq in cw. should I call "de aa8kt/qrp aa8kt/qrp or just aa8kt/qrp aa8kt aa8kt or just call aa8kt ? Tnx fer advice

Peter AA8KT

Hello Peter,

Welcome to the neighborhood.

Mel

.

K0RGR
03-20-2014, 11:49 AM
I have a very small tuner that I have used from hotel rooms - 1/4 wave wire out the window, 1/4 wave wire on the ground lug for the tuner running around the baseboards in the room. This works fine for 40 meters and up. It can be done without the tuner with judicious tuning and pruning, and that would, indeed be more efficient than using a tuner. Two radials are significantly better than one.

W9JEF
03-20-2014, 11:58 AM
I have a very small tuner that I have used from hotel rooms - 1/4 wave wire out the window, 1/4 wave wire on the ground lug for the tuner running around the baseboards in the room. This works fine for 40 meters and up. It can be done without the tuner with judicious tuning and pruning, and that would, indeed be more efficient than using a tuner. Two radials are significantly better than one.

Two radials--run as much as feasible in opposite directions.

K6BSO
03-20-2014, 01:03 PM
The Ten Tec Argonaut 505 I picked up from Ron just arrived. Looks like I'll be joining the ranks of QRP ops real soon now.

K7SGJ
03-20-2014, 02:13 PM
The Ten Tec Argonaut I picked up from Ron just arrived. Looks like I'll be joining the ranks of QRP ops real soon now.


Great. Let me know when you want to give it a try. I'll hook up the Yaesu 817 or the Icom 703, and we can try QRP somewhere. I just got he OCFD up a few days ago, and I put a remote tuner at the base; it seems to tune 160-10 FB. I'm in the process of pulling out some stuff to sell, and putting in some of the other radios I have, so it'll be a couple of days yet. I haven't had a chance to make any contacts since I've been busy fixing radios for folks. I also just finished my annual 2 stroke engine marathon, and got the chain saw purring and all the weed whackers ready to wackaway. If I'd have bought some stock in the fuel line industry when we built out here, I'd be a rich old bastid by now. The frigging weeds are terrible with all the nice weather and the rain you sent us a couple of weeks ago. However, the rattlers love slithering through it.

kb2vxa
03-20-2014, 05:22 PM
Just be careful, rattlers don't appreciate being whacked!

K7SGJ
03-20-2014, 05:42 PM
Just be careful, rattlers don't appreciate being whacked!

Our Jack Russell found that out the hard way. I should post some pictures of her head. It was about three times normal. Problem is, she still hasn't learned. Any creature that moves, she is on it.

kb2vxa
03-21-2014, 07:14 AM
A Jack Russell is made of springs. Perhaps a few shims in the right places will stiffen the ones she needs to jump in time. Big head huh? Now you have a Bull Terrier. (;->)

KC2UGV
03-21-2014, 07:54 AM
I'm assuming you have a key etc. You may want to think about a dipole or OCFD for the antenna since you are only using 40 meters. And, since you will be in the cw portion, an antenna tuner won't be necessary, as long as you "prune" the antenna to the right length. That way, you will have a better chance to maximize you signal by matching the antenna to the rig.

Whenever you are ready to get on the air for the first time to check out the station, make a post here. I'm sure several of us can be around to lend an ear to see if we can hear, and/or work you. Good luck with the project. Glad to see that cw is of interest to you.

Totes on the dipole.

If you're running a pixie, you don't have much power to lose. A longwire is a lossy, imperfect antenna. Same with advice on the tuner: Skip it, you don't want to incur the losses.

W3WN
03-21-2014, 10:04 AM
To amend the question, for qrp operators out there. I am getting a 40meter Pixie tranceiver with a CW decoder and will be running a longwire. Is there anything else I need to get on the air??Are these the same Pixie's that are advertised on eBay all the time? I'[ll be very curious to hear your reaction to it, once you've had it a while.

More than anything else, you need a good antenna. Not necessarily a GREAT one, though it helps, but a good one. If your antenna does not perform well, you won't be heard, even if you're running 100 W or 2 kW.

Before I got married, I operated an old Atlas RX 110 with the TX 110 exciter; 10 W out, 80 - 10 (no WARC). I used a random wire antenna, #24 copper enamel wire. Ran from my room, down the hall, out N3CLE (now W3GSI, his dad's call)'s window, up the side of the apartment building, across the attic, and down the front. (Red colored enamel blends well with bricks!). No ground. Call it a 7/8 half-assed loop. I worked a ton of stuff on 80 & 40 on it, including completed 80 & 40 SSB WAS. It didn't perform as well on the upper bands; but since I worked most days, that didn't really matter.

If you're running a longwire, you'll need a decent transmatch for it. Something like the Ten Tec 227 or 228 is highly recommended (the 228 includes an SWR bridge). The TT 247 & 291 tuners are also very similar, but don't have an antenna switch included; you might not need that now, but down the road, those do come in handy. AEA had a similar transmatch (ET 1), which had a dual-needle meter; I've come to prefer the dual meter SWR bridges over time, so if you can find one of these, it's worth it.

Don't forget some ground radials for the longwire.

W3WN
03-21-2014, 10:09 AM
The Ten Tec Argonaut 505 I picked up from Ron just arrived. Looks like I'll be joining the ranks of QRP ops real soon now.I liked that rig. Ironically, when I worked in the ham store, I sold the 509 & 515 Argonauts, but never that one.

Oh, in case I didn't make it clear... the TT "banana" mike should work just fine with the 505, but it has the wrong plug on it. The other mike was given to me because it had the right plug, I just never got around to taking it off. Don't know if the other mike works or not... it was given to me for the plug.

W9JEF
03-21-2014, 11:52 AM
.



For a random length wire antenna, you can make a tuner.
Wind your own coil, connect one end to the xmtr output,
the other to the antenna, and a variable capacitor to ground.
If you're QRP, you can liberate one from an old AM radio.

n0iu
03-22-2014, 10:53 AM
Before I got married, I operated an old Atlas RX 110 with the TX 110 exciter; 10 W out, 80 - 10 (no WARC). I used a random wire antenna, #24 copper enamel wire. Ran from my room, down the hall, out N3CLE (now W3GSI, his dad's call)'s window, up the side of the apartment building, across the attic, and down the front. (Red colored enamel blends well with bricks!). No ground. Call it a 7/8 half-assed loop. I worked a ton of stuff on 80 & 40 on it, including completed 80 & 40 SSB WAS. It didn't perform as well on the upper bands; but since I worked most days, that didn't really matter.

So are you saying that after you got married the antenna did not work as well?

Crap! No wonder it is taking me so long to get those additional DXCC endorsements!

W3WN
03-22-2014, 07:00 PM
So are you saying that after you got married the antenna did not work as well?

Crap! No wonder it is taking me so long to get those additional DXCC endorsements!Don't miss a trick, do you?

Nah, after I got married, I moved out of the apartment building and in with my wife, so the antenna was left behind.

We all mistakes. As it turned out, that was a huge one. Of course, if she hadn't pushed me to go back to school, which put so much stress on the relationship that it fractured, I would never have gotten the internship at USX, which led to the job at AGH, where I met the boss. So maybe it all works out for the best.