Quiet Enough for QRP?

[WU2D]

I am hearing about some amazing feats with  Dave Benson, K1SWL's Small wonder Labs AM REtro 75.

Tonight I put out a CQ with my new J38 Key attached to an ARC-5. I heard a weak reply in the R390A.You know when you tune back and forth expecting a stronger signal and looking to see what you are doing wrong? But everything looked good - he was simply weak. This was 9PM on 80M.

We definitely had some QRN tonight and I did not get the call so so I waited until he called again and cinched her down to the 100Hz position. It turned out to be Michael Rainey AA1TJ using a one transistor rig at 80mW out and copying me on a crystal set with a tunnel diode BFO. Now that is bit eccentric.

So I told him that I would play fair and I brought my two 76 tube 1935 vintage regen on line. I spotted by tuning till I heard the beat note of the regen on the R390A and then I plopped on the cans. There was a stronger station in there too but I zero beated him and Mike's signal popped right out. No problem.

It may be getting quiet enough for some lower power AM soon.

Mike WU2D

[W1UJR]

Low power AM is a blast!
I usually fire up just after lunch on weekends, band is nice and quiet.
Any time you want a sked OM just let me know.

[WB2EMS]

I've had some QRP fun with the ICOM 703 on 75. I'd be up for giving it a try sometime in a group.

Tunnel diode BFO, wow that is esoteric. 

[k4kyv]

Life's too short for QRP.

[w1vtp]

1 watt + really good ant = 59 sig

100 watts + crappy ant = 57 sig (if you're lucky)

[w3jn]

GPT-750+mediocre ant = 40 over

[Todd, KA1KAQ]

GPT-750+mediocre ant = 40 over

Inspiring the now-famous quote heard on 40m:

"When W3JN keyed up, the QRM QSYed!"

KW-1 + mediocre aerial = 32V with impressive array! 

QRP stuff works best during the day into early evening on 75-80. 40 is a bit easier. Though lately with good conditions, I've worked a couple guys up north with 30 to 100 watts. Another night a guy in 8 Land was in the noise with 125 watts. 10 minute transmissions, too.

Saturday night while working Jim WB2EJG in Oneida with his 100w DX-100B, we were joined by Dave N8LGU from W VA. Dave was running 10 watts from a ricebox into a 20' wire (inside his house, I think) and was reasonably good copy considering his power level. He didn't stick around due to his low power, respecting the QSO in progress. But it just shows ta go ya. He's itchy to get back on this fall with a big rig he's working on.

Fortunately I got my QRP operating out of the way back in the 80s-90s when it was truly challenging to attempt AM with anything under 200 watts. QRP is fun as long as you don't inflict it on QRO groups.

[WB2EMS]

I agree, QRP and QRM don't mix well. But I've made a number of contacts on the 703 with a 2.5 watt carrier, even when it's been busy. During Steve's event last fall, I worked a half a dozen stations on the frequency where Kerri was holding forth with good signal reports from the other stations. Not what I would choose to go head to head with slopbuckets, but on a well behaved frequency it seems to get out surprisingly well. OTOH, at the other end of the spectrum is the SDR-1000 and the TenTec Titan 425. It's nice to have options.  Embrace the power of "and".

[The Slab Bacon]

Life's too short for QRP.

Yea, What he said! ! !    

[KF1Z]

Been having much fun running the new 12 watt, 3 band Class- D rig.
I need to build the companion reciever now and have a 12 volt portable transciever.
(not that I ever go anywhere....)


Also, the SDR mono bander at 1 watt carrier, and the 160-6 meter SDRs I've been building at 2-2.5 watts carrier...


Building all these rigs...talking to plenty of folks,  can't  see how that's shortened my life any. 

Anyone can run 3 or 4 times the limit and make contacts.

[KA1ZGC]

Anyone can run 3 or 4 times the limit and make contacts.

I dunno, I can think of a few people who can't hear a damn thing no matter how much power they transmit with. 

[KF1Z]

I dunno, I can think of a few people who can't hear a damn thing no matter how much power they transmit with. 

Is that dependant on whether the elevator is going up or down? 

[KA1ZGC]

HA!!! I'd forgotten all about that!

Wasn't who I was thinking of, but yes, prime example!

[Steve - WB3HUZ]

QRP stuff works best during the day into early evening on 75-80. 40 is a bit easier.

Or late at night in the winter.


It's not about making contact for me. Sure, you can make lots of contacts running 10 millWatts. On AM, unless it's DX, I want to hear the guy loud and clear to enjoy the audio. If it's PW, I'm not interested. Life's too short to strain to hear PW stuff.

[WU2D]

GFZ's mixer injection oscillator is more than 80 mW.

[K1JJ]

Muttered after receiving a 3X3 report:

"As long as you can hear me, that's all that counts."


(Frustrated Pissweakers are people too)  

[Steve - WB3HUZ]

LOL! For sure.

GFZ's mixer injection oscillator is more than 80 mW.

[k4kyv]

If it's PW, I'm not interested. Life's too short to strain to hear PW stuff.

The weaker they are, the longer they talk.

[N0WVA]

QRP is a good way to get your antenna system in shape. You maximize performance with QRP and then when you go QRO, you really have one helluva signal. I just heard a conversation today on 40m where a station was saying its no big deal to lose 3db in an antenna system feedline. "Will not even be noticed" he said. Well, the problem with that idea is its accumulative. You make an improvement in an antenna, then an improvement in the receiver, then an improvement in your speaker to hear the other QRP operator, everything compliments the other to make a top notch station. 

[w1vtp]

HA!!! I'd forgotten all about that!

Wasn't who I was thinking of, but yes, prime example!

I remember him

[W3FJJ]

I hate to have people strain their ears to hear me, and vice versa, especially on AM
But I've had at least dozen great, arm chair QSO's (bothways) with my retro-75 (2.5w) , in last couple months.
They all been rather local contacts, less then 200 miles, I find best time is 9am in morning and 4pm in the afternoon, before band gets
noisey with QRM, and QRN or absorption too high...

[Steve - WB3HUZ]

A famous Big Strapper once said, "A dB here, a dB there, and pretty soon you're pissweak."

QRP is a good way to get your antenna system in shape. You maximize performance with QRP and then when you go QRO, you really have one helluva signal. I just heard a conversation today on 40m where a station was saying its no big deal to lose 3db in an antenna system feedline. "Will not even be noticed" he said. Well, the problem with that idea is its accumulative. You make an improvement in an antenna, then an improvement in the receiver, then an improvement in your speaker to hear the other QRP operator, everything compliments the other to make a top notch station. 

[K1JJ]

A few things to show how valuable a few db are:

The difference in forward gain between a standard 1/2 wave dipole and a full size 3 element Yagi is only about 4.5 db.  Why is it guys with Yagis are so much louder than guys with G5RV's? It's usually cuz the Yagi guys are more experienced and are doing other things correctly too. It all adds up.

The difference between a 75M mobile whip antenna on a truck and a full size dipole at 60' is only about 12-15db based on my own on-air field measurements.

On ssb, all other things being equal, someone with just one db signal strength advantage will usually be picked out of a pile-up first.

There's many more examples, but the bottom line is that the biggest stations on the air are the ones who do everything technically right. We may not think a few db means much when we see the effects of fading swing a signal 20db at times, but remember that everyone is in the same boat and averaged over time, that few db will show itself for better or worse - relative to everyone else.

T

[Steve - WB3HUZ]

The difference in forward gain between a standard 1/2 wave dipole and a full size 3 element Yagi is only about 4.5 db.  Why is it guys with Yagis are so much louder than guys with G5RV's?

The other thing is that the G5RVs are usually at 50 feet or less and the Yagis are usually at 100 feet or more on the lower bands. At the lower angles, the difference will be a lot more than 4-5 dB.

I would never want to give up 3 dB in the feedline, no matter what antenna I was using. Why throw away half your power in heat? That's just stupid and as Tom points out, in many situations it WILL be noticed (or you won't be noticed in a pileup or during marginal conditions).

[K1JJ]

Yep.

And how about receiving noise?  Having good ears is subtle and no one will know it by hearing you talk. But the difference between listening on a dipole and Yagi (at the same heights) is tremendous.  Taking the opposite approach, KNOCKING DOWN atmospheric noise off the back of the antenna by 20db lets us hear weak signals  1-2 layers down that we normally can't hear with a bi-directional dipole.

That's part of what I mean by doing everything right. A lossy feedline kills transmit signal but won't affect receiving much unless it's really deaf, like using a 160M coax-fed dipole on 75M. There's many, many aspects to creating a fully optimized station for a particular band.  Understanding propagation and the best times for certain contacts is key too. Some guys know a band so well they call for certain areas at certain times and score most every time.

T