Author Topic: My QRP Experiment Was A Huge Success!  (Read 18100 times)

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Tevin

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My QRP Experiment Was A Huge Success!
« on: February 14, 2015, 10:17:06 PM »
This is a continuation of the ongoing story of my old go box, which was too big, too heavy, and a massive fail.

I've spent the last few months trying to decide if I should include HF in my new & improved porta-station. It would require new equipment and of course a significant cash outlay. I have money to spend but I don't have money to waste. I'm of the opinion that HF is not mission-critical for most prepping purposes. But as someone who wants to be a "full service" ham when SHTF, I feel I need to include it because there's a good chance I'll be the only guy within miles who knows how to do something besides kerchunk a repeater. People are depending on me to be the "electronics wizard".

I decided to look into QRP as a serious option. I never tried it and have only a generic knowledge of the topic. It would solve a lot of problems of weight and space, with a tradeoff of lower power. So to find out if I could get by on QRP, I turned my FT-950 output power down as far as it will go, which I estimate to be 5-7 watts (the meter resolution is poor at low levels). For sure it was less than ten watts.

Long story short: Without hardly even trying, I got a 5x9 signal report on 40 meter phone from stations 500 and 1100 miles away! And that was using an antenna that isn't that great. I was shocked.

I'm still going to run a few more tests, but my initial impression of QRP is that it is not just for experimenting and contests. It can be a practical everyday comms method.

If I add an 817ND to the mix, I'll keep my FT-2900 in there as well for higher power on 2-meters. I have enough solar stuff laying around to make a more than adequate power source. The whole package will be considerably smaller, lighter, and more versatile than the beast it is replacing.

So I have no heavy questions or anything like that. I just wanted to share my excitement. I never gave much thought to QRP but now that I've tried it I think it's worth looking at.







spacecase0

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Re: My QRP Experiment Was A Huge Success!
« Reply #1 on: February 15, 2015, 12:33:43 AM »
that is good to here how well it worked

if the power grid ever fails, QRP will work even better
usually you need power to cover over the QRM of the world,
that QRM vanishes if the grid fails
then there are some days that you just need power to get past what the sun is doing, but they are not to common.

I like the 817 and 2900 due to being quite low power requirements for what you get
they are the ones I use when I am running on solar
have you looked at the Tokyo Hy-Power HL-45B to go with the 817 ? it is still pretty efficient with that amp
http://www.eham.net/reviews/detail/7941

DragoSapien

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Re: My QRP Experiment Was A Huge Success!
« Reply #2 on: February 15, 2015, 09:29:08 AM »
I have to have HF in my go box. Out here where im at UHF/VHF will be only for the group. If the repeaters go down there no other way to talk to other towns with out the HF for me. Good move on the QRP. Im doing the same thing playing with it.

XJP5

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Re: My QRP Experiment Was A Huge Success!
« Reply #3 on: February 15, 2015, 10:34:59 AM »

I decided to look into QRP as a serious option. I never tried it and have only a generic knowledge of the topic. It would solve a lot of problems of weight and space, with a tradeoff of lower power. So to find out if I could get by on QRP, I turned my FT-950 output power down as far as it will go, which I estimate to be 5-7 watts (the meter resolution is poor at low levels). For sure it was less than ten watts.

For the sake of battery life, I'm wondering what your current draw in A/h is at that low power setting? Do you have any way to measure it accurately Tev? I'm getting ready to experiment with a backpack portable configuration myself and am curious. Thx.

Tevin

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Re: My QRP Experiment Was A Huge Success!
« Reply #4 on: February 15, 2015, 11:03:18 AM »
that is good to here how well it worked

if the power grid ever fails, QRP will work even better
usually you need power to cover over the QRM of the world,
that QRM vanishes if the grid fails
then there are some days that you just need power to get past what the sun is doing, but they are not to common.

I like the 817 and 2900 due to being quite low power requirements for what you get
they are the ones I use when I am running on solar
have you looked at the Tokyo Hy-Power HL-45B to go with the 817 ? it is still pretty efficient with that amp
http://www.eham.net/reviews/detail/7941

I experimented a little more this morning, this time 20 meter phone during the day. I heard the same guy I spoke with last night at 1100 miles on 40 (he is in a QSO party) and tried him again. He could kind-of hear me but not enough to call it a legitimate contact.

I heard another guy, about the same distance, but he was running a special events station and there was no way I could break through the pile up.

In both cases, I could barely if at all hear the other stations replying to these guys. The ones I did hear were all on that side of the country.

Today's experiment was not successful but it is just one day on one band. We all know ham radio is a lot like fishing and sometimes the fish don't want to play. I'm not discouraged. QRP has been around as long as ham radio itself and is a proven performer. I'm not doing anything amazing & new.

I found some linears for the 817 on eBay but they were clearly cheap Chinarigs that I would dread having to depend on in SHTF. As best I can determine, the Tokyo Hy-Power is the only one worth having, and of course the design quality is reflected in the price tag.

Drago: My reservations about HF for SHTF come from my belief that if things get really bad, you're not going to care about what's going on five states away. Yes, I know there will always be exceptions, but 95% of your comms will be local. If you are in a situation where the range of VHF/UHF is not enough but you're still too close for DX (I'm thinking in terms of regional cities, as you mentioned), then you'll need to go HF ground wave. That requires brute power and QRP will not pull it off anyway. Sometimes there is no substitute for a big ass linear.

spacecase0

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Re: My QRP Experiment Was A Huge Success!
« Reply #5 on: February 15, 2015, 12:01:14 PM »
the Tokyo Hy-Power amps are a bit pricey, but they work fantastic,
to bad you can't get new ones anymore,
I got mine used for 450$
if I remember correct, it pulls 8A for 45W out,

here are the power usages on the FT-817
http://www.n0usr.com/817/power.htm

so 45W out with the radio and the amp takes about 10A peak,
and with SSB, you are pulling a pretty low average current
it is something like 3 or 4 A on transmit
and on receive the amp pulls almost no current, so you only have about 350mA on receive

I use a 3.5F cap with the battery if the battery is small (like only 12AH ), or if I am running solar only
and it helps the voltage from fading on the peaks of the SSB

my ft-857 pulls way more current for the same 45W out,
even if I put it in battery mode it still takes more power than the 817 with the amp

Tevin

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Re: My QRP Experiment Was A Huge Success!
« Reply #6 on: February 15, 2015, 08:22:04 PM »
For the sake of battery life, I'm wondering what your current draw in A/h is at that low power setting? Do you have any way to measure it accurately Tev? I'm getting ready to experiment with a backpack portable configuration myself and am curious. Thx.

I do not have a dedicated/specialty QRP radio, so for my experiment I'm using my FT-950 with the output turned down to about five watts. The current on the final amp at that point is about 2-3 amps (there is a meter setting for this). Keep in mind that is just for the finals, not the entire radio. My home station is not a good apple-to-apples comparison to a backpack-based setup.

I'm on the fence as to run with an 857D or the 817ND in the go box. The ND is less expensive, lighter, and smaller, but I would be committed to permanent low power. I can always turn an 857 down but I can't turn an 817 up. I understand spacecase0's excellent point about adding a linear and having it both ways, but for right now I want to keep it simple. The "well, I can squeeze in one more thing" attitude is what got me into this mess to begin with. 
« Last Edit: February 16, 2015, 08:25:50 AM by Tevin »

Tempstar

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Re: My QRP Experiment Was A Huge Success!
« Reply #7 on: February 15, 2015, 08:46:00 PM »
Tev, I used an 817 for a while, and loved the battery option, but missed the power option. Then I got an 857, just never liked it but it was great for low power ops, and I found 20 watts to be my number most of the time with a G5RV. Now my portable is an 897 in a US night vision case. I got away from the rack cases because I had to haul a lot of air. Now I just put some feedline and the case in the truck and go, usually with the Chameleon set-up. Nothing beats pulling over in the mountains at a roadside table and working stations with 1-10 watts while having lunch! Oh, I have a 50' 10 ga SJO cable for power from the truck. No sense lugging the AGM along.....
"Preparedness is a lot more than just buying stuff"

Tevin

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Re: My QRP Experiment Was A Huge Success!
« Reply #8 on: June 15, 2015, 09:05:02 PM »
Well four months later, a follow up...

It was time to quit fidgeting and overthinking this and execute a plan. Enough reading and pondering and watching ham radio equipment review vids on YouTube.

I decided to trade high power for portability and efficiency. I ordered a FT-817ND and expect it to arrive in the next day or two. Haven't yet determined how it will be powered; I am leaning towards a 20-30 watt solar panel and a 5-7 aH battery. Also have not decided on a to-go format: back pack, hard case, rack mount, whatever.

I have some portable home-brew antennas but they are not quite as portable as I'd like them to be. I'm working on an idea for an ultra-light antenna that will roll up and fit in the bag and should not need an antenna tuner. If the idea works it will be epic cool and I will gladly share it here.

My plan has finally stopped being just a plan. Will post updates as needed.

AD

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Re: My QRP Experiment Was A Huge Success!
« Reply #9 on: June 15, 2015, 11:20:21 PM »
Keep it coming. 
The only dumb question is the one that did not get asked!!

Tempstar

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Re: My QRP Experiment Was A Huge Success!
« Reply #10 on: June 16, 2015, 08:02:00 PM »
Tev, Check out Carl's video here, plus others he has on youtube.

https://www.youtube.com/watch?v=A3ctImax9Io
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tazdevil

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Re: My QRP Experiment Was A Huge Success!
« Reply #11 on: June 16, 2015, 10:17:52 PM »
I don't run qrp with a go kit, but as far as a inexpensive 12vdc amp, I bought a RMItaly KL405v, rated at 200 watts. I use it to run data to take the load off of my radio finals, 5 watts drive gives me 100 watts out. I have used it in my shack just for experimental purposes, but it will go into my portable load out for certain.  $220 shipped from Hong Kong and I got it in 4 days.  Pretty good bang for the buck IMO. www.88radio.com

spacecase0

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Re: My QRP Experiment Was A Huge Success!
« Reply #12 on: June 17, 2015, 01:03:07 AM »
one of my friends got the RM Italy KL 505,
seems to work fantastic,
but he also does not push it past 300W on SSB

tazdevil

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Re: My QRP Experiment Was A Huge Success!
« Reply #13 on: June 17, 2015, 08:21:42 PM »
A truck driver friend uses the 505 with a hamstick, makes that mobile sound great. He can't push it too much past 200w

spacecase0

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Re: My QRP Experiment Was A Huge Success!
« Reply #14 on: June 18, 2015, 12:18:35 AM »
I guess the hamstick antennas are only rated for 250W
but getting enough current to the 505 at the correct voltage in a mobile setup is likely hard
that thing needs a pretty big power supply