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Author Topic: STARTING OUT QRP  (Read 5368 times)
K8AXW
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Posts: 7042




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« Reply #30 on: May 06, 2019, 11:01:38 AM »

If you're an old hand at HF CW...all of these suggestions are right on.  But, if you're STARTING out HF doing QRP CW I agree with the "getting out in a nice park" but just beat out CW on a rock with a piece of pipe.  Maybe someone will come through and answer you.

You'll have  more fun doing the same thing in a rattlesnake den.

Getting started in HF is great fun even though we're at a sunspot LOW but doing it handicapped is not a great idea. Just MHO.
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A Pessimist is Never Disappointed!
N8AUC
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Posts: 646




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« Reply #31 on: May 06, 2019, 11:29:52 AM »

Also the current drain on transmit for an 100 watt class rig turned down to 5 watts is much greater than a 5 watt running 5 watts because of the bias current needed to bias the final transistors.  This is typically about 4 amps of current before the first dit or the first bit of speech is uttered.  Check it out. The bias current for a typical 5 watt QRP rig is way under an amp, usually just a couple hundred milliamps, as compared to 4 amps bias current for a typical 100 watt rig upon key up.

Don't get me wrong, there is great advantage to having a rig with a built in "amplifier" on tap with just turning up the power with a knob or menu setting. But you have to budget your battery accordingly. 100 watt rigs turned down to 5 watt QRP power are not battery efficient.

On some rigs this may be true. But it isn't true on an FT-857D.
I've measured the current draw both on that radio and my FT-817 in order to determine battery requirements for field operations.
The FT-817 draws 2 amps on transmit when set to 5 watts output CW.
The FT-857D also draws 2 amps on transmit when set to 5 watts output CW. It draws about 4 amps at 20w output, and 5.5A at 30w output.

73 de N8AUC
Eric
« Last Edit: May 06, 2019, 11:32:44 AM by N8AUC » Logged
AA4PB
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Posts: 15066




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« Reply #32 on: May 06, 2019, 01:06:19 PM »

As an example, an Elecraft K1 draws 700 to 900 mA at 5W CW output. It would get at least twice the battery life for a given battery type than the FT-817 set to 5W output.
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Bob  AA4PB
Garrisonville, VA
VK3YE
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Posts: 267


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« Reply #33 on: May 07, 2019, 07:23:52 PM »


On some rigs this may be true. But it isn't true on an FT-857D.
I've measured the current draw both on that radio and my FT-817 in order to determine battery requirements for field operations.
The FT-817 draws 2 amps on transmit when set to 5 watts output CW.
The FT-857D also draws 2 amps on transmit when set to 5 watts output CW. It draws about 4 amps at 20w output, and 5.5A at 30w output.

We listen more than we transmit. So the critical thing for portable QRP is receive current consumption.

The FT857 uses 2 - 3 times the current on receive than the FT817. Some measurements here: https://www.eham.net/ehamforum/smf/index.php?topic=67668.0

If you value truly portable QRP for hours on end you won't take anything that draws more than the FT817. And if your space/weight constraints were tighter you'd take something that draws even less. I've received amateurs on homebrew receivers that draw less than 10 mA - that shows how much current hogs commercial gear can be. 
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Peter VK3YE

One ham radio post each day. Visit http://dailyantenna.blogspot.com
Author of top selling $US 5 amateur radio ebooks on antennas, QRP, getting started and more. See http://home.alphalink.com.au/~parkerp/vk3yebooks.htm
W1VT
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Posts: 3399




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« Reply #34 on: May 08, 2019, 12:21:58 PM »

I had a lot of fun doing 6M QRP with an HF dipole from a 2nd floor apartment. 
During the summer E-skip season I found it easy to make 1000 mile contacts running SSB. 
I worked enough grid squares to get my  first VUCC award!

The E skip season is only a few months and propagation is really unpredictable, but 6M SSB can be a very fun
way to do voice with a very modest station.

Zak W1VT
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N2DTS
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Posts: 967




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« Reply #35 on: May 08, 2019, 05:24:29 PM »

What was the size of the dipole?
I have one up and made some 6 meter contacts but the trees trashed it and I need to re do it.
It is/was a fan dipole but now its more of a ball of wire hanging above a giant cherry tree!
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VK3YE
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« Reply #36 on: May 09, 2019, 06:58:22 PM »

The E skip season is only a few months and propagation is really unpredictable, but 6M SSB can be a very fun
way to do voice with a very modest station.

10 & 6m SSB are great fun over summer. Video below shows some portable operating with 5w to a dipole. Contacts up to 2500km.

https://www.youtube.com/watch?v=Mn0_xnTkgmg

These bands can however be quiet for much of the rest of the year. Whereas 40m (and 80m at night) has activity and contacts possible with QRP every day.
So I'd suggest getting equipped for these bands first then 10 & 6m.
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Peter VK3YE

One ham radio post each day. Visit http://dailyantenna.blogspot.com
Author of top selling $US 5 amateur radio ebooks on antennas, QRP, getting started and more. See http://home.alphalink.com.au/~parkerp/vk3yebooks.htm
W1VT
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Posts: 3399




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« Reply #37 on: May 09, 2019, 07:18:58 PM »

It was 86 ft and fed with open wire.  Even better is a small Yagi or Moxon beam. 

Yes, it is a short season, but 6M SSB  is one of better options for doing voice with very modest station.

Zak W1VT
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N9LCD
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Posts: 125




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« Reply #38 on: May 12, 2019, 08:03:21 AM »

I thank everybody for their advice and opinions.

Starting out with HF QRP & an indoor antenna was a last ditch option.  I wanted to try HF without necessitating major collateral work on the house.

Some years ago I had plans for a roof mounted VHF & UHF antenna farm that would be professionally (gasp!) installed.  The contractor needed the blueprints for our house.  That was $750 for the set of plans.

Well, the house wasn't built as drawn.  In Chicago, Mr. Franklin is a very persuasive negotiator.  So we had to open the cathedral ceiling to see what was used for the rafters and roof deck.  The rafters were manufactured lumber, glorified 2x4's, and the roof deck was plywood.

A royal waste of money!

A major job to repair and retape the ceiling.  And repaint the hall/library and stairway.  The shade of the "replacement" paint disn't match the shade of the original paint.

As for operating outside, I considered operating in the back yard with a portable antenna.  That one didn't go too far.  It would be kind of hard to operate when you're under the main runways in and out of O'Hare.  And on the main drag to the Canadian National container yards in Schiller Park.

As for operating in a park, I'd be reluctant to take $600+ worth of gear out to one of the without somebody with a Mossberg as cover.

Maybe.  One of these days...  In what looks like the far, distant future.
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EI3IBB
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Posts: 26




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« Reply #39 on: June 10, 2019, 02:25:56 PM »

I'm a new ham and I use the Xiegu X5105 portable with the hyendcompany.nl portable 4 band mini 100 watt antenna and I've made contacts on it no problem with the 5 watts SSB.

The antenna seems pretty efficient, not using radials or even earth and furthest I got so far was 875 miles on 20 meters in the early afternoon. I haven't used it much yet.

I'll be bringing this setup to the Austrian Alps in July, easy deploy and it works. Very compact setup.
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KB7FHK
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Posts: 29




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« Reply #40 on: June 24, 2019, 08:57:11 PM »

I was a poor ham when I started. A Vectronics DC RX kit and a rock bound TX I built from scrap parts I got at ham fest. Antenna was split speaker wire. I was a qrp op out of necessity. Of course you can't get the stations you want right away but you learn how to get the stations you need. Listening, learning propagation, and technique come from qrp operations. Skills a lot of hams with big rigs from the start still learning after years of ops.
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KX4QP
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Posts: 404




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« Reply #41 on: June 25, 2019, 04:52:39 PM »

Well, I finally got my Cricket 80a on the air on Field Day.

After waiting all day for wind so I could launch the kite I'd planned to use to carry the half-wave dipole, I hooked up to a similar antenna in a tree that was temporarily out of use and sent a few CQ calls.  I had the original crystal that came with the Cricket kit, 3.579 MHz, as well as crystals I'd purchased on eBay at 3.535, 3.550, 3.560, and 3.910.  Of that lot, the only one that was covered up with either digital traffic (why are folks sending PSK31 in the CW-only part of 80m?) or lots of CW stations just a little bit off my frequency -- who almost certainly couldn't hear me because I was outside their filter width.  I found 3.560 was open, so I started sending CQ CQ FD NC4AR (the club sign for Field Day).  I'd send for 1-2 minutes, then listen for a while.  The radio is said to put out around 1W on a fresh 9V battery.

After an hour I gave up (and the guy with the 80m antenna wanted to use his rig again).

In hindsight, Field Day is probably the worst possible time for someone whose Morse is shaky and has only 1W transmit power to try to make CW QSOs -- but I was there, people were bugging me to operate (and I had no real interest in the contest-style "get the info and move on"), and I wanted to try out the little radio and my kit-built American Morse Equipment KK-1b straight key.

I belatedly thought to check the Reverse Beacon Network (Monday morning), but found that the club call wasn't to be found for any Field Day times; I presume that's because RBN is a manual operation of logging a spot, rather than automated equipment to pick up digital or CW calls.
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K5LXP
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« Reply #42 on: June 25, 2019, 07:48:10 PM »


I think despite "failure" to make a contact you got some valuable experience.  You also tried, which is more than a lot of folks seem willing to do these days.  Field Day can be both a blessing and a curse, there's a ton of stations on to work but they're all not necessarily looking just to work you.  I find a lot of running stations (the ones calling CQ) seem to be using some fairly narrow filters and if you're off a little bit, they just don't hear you.  Other ops are just outstanding, they'll pull a QRP signal out of the mayhem and go above and beyond to make the QSO happen.  So *next time* maybe set yourself up with equipment that improves your odds a little bit.  Hopefully you got a chance to listen in or operate some of the other stations there.

Mark K5LXP
Albuquerque, NM
 
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N8AUC
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Posts: 646




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« Reply #43 on: June 26, 2019, 08:07:44 AM »

Congrats on participating in Field Day! Take what you learned from your experience, use that to start figuring out how to improve
your situation for next year. It's definitely a process, and by participating this year, you've taken the first steps. The more you do it,
the better you'll get. Be patient, don't give up, and you'll get there.

As for your question about PSK31, they start at 3.570, and under crowded band conditions, they spread upwards from there.
So what you observed, is kind of normal. The data modes usually run at the top part of the CW/DATA sub bands, in accordance with the
band plans. Note that on the HF bands, the CW allocations are not exclusive to CW. They are shared between CW and data modes.
The only place where there are exclusive CW allocations are on 6 and 2 meters.

I was talking with a friend of mine who ran QRP the whole time at another site using an FT-818ND. He was battery powered, using a wire vertical antenna.
Between SSB and CW, he managed to make a little over 100 contacts while running 5 watts. Which I thought was pretty darned good.

I used my FT-857D on CW, running 20 watts on 40 and 20 meters, solar powered, with a homebrew wire dipole. That setup worked pretty well this year.
I don't have enough transmitter power to call CQ and run a frequency, so what I do is "hunt and pounce". I start at the top of the band, and slowly tune
down in frequency, and try to work anyone I can hear. At 20 watts, sometime I get 'em, and sometimes I don't. When I get to the bottom of the band, I
go back to the top and repeat the process. Maybe I'll get 'em next time through the band.

I need to make some modifications to my homebrew battery box though, so I can increase my transmitter power a bit. The current measuring circuitry
in the battery box needs to be beefed up to enable that. So that's what I have to work on before we do this again next year.

73 de N8AUC
Eric
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KX4QP
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Posts: 404




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« Reply #44 on: June 28, 2019, 04:39:41 PM »

Mark, Eric, thanks for the encouragement.  I thought I'd be able to keep my kite (and hence antenna) up most of the night, since we'd been having pretty steady wind between 5-10 mph for the previous week.  If I'd known early in the day the wind wasn't going to rise, I could have gotten my antenna up in the trees next to the other 80m dipole and the 20m end fed.  Don't know if I'd have been able to hear anything with that setup, however (another transmitter on my band just feet away, albeit in the phone section instead of CW).

By next year, I ought to be able to have my SB-102 running.  That'll give me up to 100W on 80/40/20/15/10, SSB or CW.  I should also have another CW QRP battery rig going on 40m (it's a kit, with tubes, should be done in a few weeks, pending spare time).  I'll probably stick with CW, since I was the only one trying to operate CW at our club site, and seemed to be the only one who knew Morse even poorly.  Another year of practice ought to help there, too.  I also plan to investigate whether raising voltage a little is safe for the Cricket -- going from 9V up to 12V ought to nearly double the output power.
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