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Author Topic: Does QRP AM make any sense?  (Read 24079 times)
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WD8BIL
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« Reply #25 on: August 26, 2011, 01:11:01 PM »

No matter what power level you run........

PUT SOME AUDIO ON IT!!
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The Slab Bacon
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« Reply #26 on: August 26, 2011, 01:15:40 PM »

No matter what power level you run........

PUT SOME AUDIO ON IT!!


That is one thing no one ever has to tell me  Grin  Grin


Always remember the first rule of the piss-weaker:

THE WEAKER THEY ARE THE LONGER THEY TALK!  Angry  Shocked
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kg8lb
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« Reply #27 on: August 26, 2011, 01:21:07 PM »

 Lessee here. Who else matters (?) Two fellows in MD living about 5 miles apart running the legal limit . Sure they can hear each other. But the fellow in Kentucky may not be able to hear another station in Ohio Tnx to the QRM.

 What else matters ?
Why don't broadcasters use 20 watts ?
In a thread that simply asks about the viability of low power AM Huh

  Some folks may not care to run QRP AM, that is a different matter. Still others operate QRP AM regularly with good results.
We are not broadcasters in any event. That is why we have a lower power limit and a gentleman's guideline to run lower power when possible.
  We usually run lower power here but the legal limit is just a flip of the switch away if wanted (but rarely needed) Grin

 Of course , as Buddly sez, modulate well.
 The QRO bunch manages to fillibluster too , Mr Slab  Wink

I started listening on 3880 at 8:35  tonight (8-25) There were two AMers, each running fairly long xmsns, beginning with sigs around S5-7, and gradually increasing to 20 over 9. The problem, as I saw it,  there were no id's, with the QSO running more than a half hour. One was 'Blaine', but the other gave no name.


Walt
 Old sayings ain't always so.
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KM1H
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« Reply #28 on: August 26, 2011, 07:39:00 PM »

Quote
Why don't broadcasters use 20 watts ?

They sure do and often 10dB less than that. Lots of day/night stations have to both reduce power at dusk but also change antenna pattern if they are a multi tower station.

A QRP 2W to a big stick is still enough for local listeners within walking distance. My favorite station is WXEX 1540 which is 5KW day, 2500W at critical time and 3W at night. I need a good outside antenna or Beverage during the day as Im already in the fringe area. Not a chance of hearing at night so I use the PC to listen to them.

WJIB is 250/5W and is OK during the day until the Toronto flamethrower takes them out.
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k4kyv
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Don
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« Reply #29 on: August 26, 2011, 09:41:23 PM »

i never did like that minimum amount of power necessary rule, just how do you judge the minimum amount of power? the more power you run, usually the better you are heard. so do you run enough power to be just barely heard or do you run enough for it to be comfortable to listen to? there are some situations such as when trying to run AM in high static when the minimum amount of power needed to communicate is the maximum you can put out.

I don't have Part 97 right here before me, but IIRC, it says minimum power necessary to maintain the desired communication. Now, what exactly does that mean? Minimum power to remain full quieting? Minimum power to maintain 100% readability? Or, does it mean you are supposed to always run right at the ragged edge? Plus, while you are transmitting, you have no way of knowing what the signal is at the other end if the other station is beyond ground wave range.  It would seem to me that rule was meant to discourage a couple of stations a couple of blocks apart from each running a KW on 75 just to chit-chat with each other, when they could be using VHF or only a few watts on one of the lower frequency bands. Once outside the local area, there are too many variables to make a citation stick for running more power than "necessary".
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Don, K4KYV                                       AMI#5
Licensed since 1959 and not happy to be back on AM...    Never got off AM in the first place.

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« Reply #30 on: August 26, 2011, 11:24:40 PM »

this is what it says:

FCC 97.313 as of August 17, 2011 -
www.hallikainen.com/FccRules/2011/97/313/

(a) An amateur station must use the minimum transmitter power necessary to carry out the desired communications. ...

I desire armchair copy.

<<<"Why don't broadcasters use 20 watts ?"

They sure do and often 10dB less than that.>>>

I apologize for being in a hurry and not choosing my words more carefully.  I should have asked (rhetorically) Why don't broadcasters use 20 watts all the time?

<<WJIB is 250/5W and is OK during the day until the Toronto flamethrower takes them out.>> 

you mean "squashed like a bug?"  Cheesy


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Patrick J. / KD5OEI
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« Reply #31 on: August 26, 2011, 11:48:56 PM »

Those ham radio articles harping on 100 watts  - well OK it works fine for SSB much of the time but a bit more is needed to do the same on AM. The articles may have been focusing on the lowest common denominator not the classical modes.
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« Reply #32 on: August 27, 2011, 12:39:42 AM »

Those ham radio articles harping on 100 watts  - well OK it works fine for SSB much of the time but a bit more is needed to do the same on AM. The articles may have been focusing on the lowest common denominator not the classical modes.

100 Watts is very doable.  One has to choose band and time to operate.  A LOT OF US in here use 100 Watt rigs.  Oh wait, you're comparing apples and oranges.  100 watts "SSB" is P.E.P.  100 watts AM is carrier.... or do you mean 25 watts carrier and 100% modulation?
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IN A TRIODE NO ONE CAN HEAR YOUR SCREEN


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« Reply #33 on: August 27, 2011, 02:22:12 AM »

OK, We'll open a leg of the three phase and adjust the bias to match. Wink

All the HF bands are big enough to handle a lot of QSO's, both big & small, no? Huh

100W TPO > 90% avg mod AM is a good level for local stuff. Kiss

I've a hard time telling the difference between slopbucket and noise. Tongue

73DG



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WD5JKO
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« Reply #34 on: August 27, 2011, 10:03:04 AM »


> Does QRP AM make any sense?

 Absolutely! Just make sure propagation is favorable, QRM an QRN are down, keep the average modulation high, and don't stay keyed down too long. QRP AM has some special considerations to take in. As said earlier, "old buzzard" transmissions on a low power AM signal that might also be under modulated will upset those in a big round table. If you check into a group of AM'ers running QRP, maybe keep the transmissions under 30 seconds each. That way the rest of the group will not lose patience with you as QSB or QRM covers you up.

Several have mentioned the Retro-75. Just remember that this QRP AM rig as designed has a low average percentage of modulation since the AMC kicks in early, and the modulation transformer saturates on audio peaks. There are several long threads about this on AMFONE. Easily fixed issues..

Jim
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kg8lb
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« Reply #35 on: August 27, 2011, 10:34:30 AM »

this is what it says:

FCC 97.313 as of August 17, 2011 -
www.hallikainen.com/FccRules/2011/97/313/

(a) An amateur station must use the minimum transmitter power necessary to carry out the desired communications. ...

I desire armchair copy.

  So do others. but we SHARE the ham bands . Still want armchair copy ?Get yourself a cell phone.
<<<"Why don't broadcasters use 20 watts ?"


They sure do and often 10dB less than that.>>>

I apologize for being in a hurry and not choosing my words more carefully.  I should have asked (rhetorically) Why don't broadcasters use 20 watts all the time?

Brilliant !..They run reduced power so others can use the same frequency at the same time without uneccessary interference

<<WJIB is 250/5W and is OK during the day until the Toronto flamethrower takes them out.>>  

you mean "squashed like a bug?"  Cheesy

I think Carl chose his words well , he usually does .  Perhaps your translation reveals a lot about your attitude and motivations ? Wink
  Doesn't have to happen on amateur radio. RE: "Why don't broadcasters run 20watts" from above
Still it is not a question of personal preference. It is about the viability of QRP on HF AM. Some proclaim QRP is not viable on HF AM..Others who have actually tried it have met with good success and operate QRP regularly. Not only "Local contacts" but even  500 to 600 miles with 2 watts on 75 AM "prime time" with good results.
73, Gary
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Ed/KB1HYS
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« Reply #36 on: August 27, 2011, 12:05:11 PM »

actually, building a really good QRP rig and then feeding it into a linear amp is a great approach. You can do all the modulation and RF stuff at low levels where component cost/size etc is not much of a problem Then when you've got that QRP rig running 5-10 watts output with good modulation and all that you can pipe it into the linear if conditions are rough.   
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73 de Ed/KB1HYS
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flintstone mop
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« Reply #37 on: August 27, 2011, 12:11:41 PM »

QRP would be like a separate category or challenge, to me. Maybe on a higher band, possibly 40M, but more like 20 and higher, the atmospherics are much less and won't cause a ruckus in your ears.
The lower bands and the QRN would be too much for anything beyond 1 minute and 'hey I just contacted a Ham in Minnesota with 5 watts AM'........200 miles from my QTH on 80M!!
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Fred KC4MOP
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« Reply #38 on: August 27, 2011, 01:06:07 PM »

george..there is a guy in orangeville, selling a johnson viking2....listed on the o.s.s. ..i think he is ve3pri...the old viker, is hard to beat...

..tim..

..sk..
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...Yes, my name is Tim Smith...sk..
Bill, KD0HG
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« Reply #39 on: August 27, 2011, 01:46:41 PM »

Could someone define "QRP" for me?

2-watt tuna tin, a 50-watt Ranger or Elmac?

Out here in the Great American Desert, it's a thousand miles + to population centers. Over land. ~500 miles makes it to Albuquerque, Salt Lake or Omaha. Most of y'all are real DX. A barefoot Ranger just won't cut it. I'm with Don on this one.
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W7TFO
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« Reply #40 on: August 27, 2011, 02:21:19 PM »

actually, building a really good QRP rig and then feeding it into a linear amp is a great approach.    

Indeed.  What Ed said.  Maybe build a Doherty for single-band op.

73DG
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kg8lb
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« Reply #41 on: August 27, 2011, 04:09:38 PM »

QRP would be like a separate category or challenge, to me. Maybe on a higher band, possibly 40M, but more like 20 and higher, the atmospherics are much less and won't cause a ruckus in your ears.
The lower bands and the QRN would be too much for anything beyond 1 minute and 'hey I just contacted a Ham in Minnesota with 5 watts AM'........200 miles from my QTH on 80M!!
Fred,
 I often work other stations at 200 miles plus . We have worked Retro 75 to Retro 75 at those distances easily and had some nice , long QSOs. The very first night I had mine on the air we made contact with a station in TN near the GA border (500 Miles Plus with only 2 Watts), he was in QSO with a SC and a PA station . We chatted for about an hour and I repeatedly asked if they wanted me to put on more power. They said the 2 watts was FB and S9+ .  One of those hams is now running a Retro 75 of his own.
 As someone said "define QRP? Last week I was in QSO with Steve out on Rattlesnake Island using the Multi Elmac @37watts and gettin S9+20 and better reports. Steve was perfect copy here as well using the excellent receiver side of the Retro 75 So , yes "QRP" is quite viable even on 75M. even at 500 miles 50 to 100 watts is quite often entirely adequate. Given good conditions and 2 watts is not only adequate but great fun.I have a few operating positions here ranging from 2 watts to the legal limit. I rarely ever find the need to use the limit  however. The most used TX here are Elmacs @37 or so watts...CARRIER.Next most used is the Viking 1 @ 100 or so . The Globe Champ and the HB legal limit are rarely even needed. And we don't even have the mandatory OWL feedline Grin As far as running an amp with the Retro 75, not for me. It really defeats my reasons for building the Retro. Just finished the Retro 40 but have not had the chance to try it out yet.
 George, If you really NEED more power you can have my Viking 1 real cheap...or one of the Elmacs...or perhaps the Globe King 500..CHEAP. PM me..I don't need the stuff.

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kg8lb
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« Reply #42 on: August 27, 2011, 04:39:22 PM »

Quote
Why don't broadcasters use 20 watts ?

They sure do and often 10dB less than that. Lots of day/night stations have to both reduce power at dusk but also change antenna pattern if they are a multi tower station.

A QRP 2W to a big stick is still enough for local listeners within walking distance. My favorite station is WXEX 1540 which is 5KW day, 2500W at critical time and 3W at night. I need a good outside antenna or Beverage during the day as Im already in the fringe area. Not a chance of hearing at night so I use the PC to listen to them.

WJIB is 250/5W and is OK during the day until the Toronto flamethrower takes them out.

 Carl, Just for the sake of clarity , I was repeating the question already posed. Not asking it myself. I was actually a bit surprised that anyone with a license had to ask !
 Thanks for the input however.
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VE3DDY
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« Reply #43 on: August 27, 2011, 06:42:43 PM »

George,
Why not try DSB. You can build a tiny DSB board for a Heathkit HW8 that works gangbusters.
Check Google for DSB and the HW8. It'll fit into almost any small AM set. You can convert a CB and use it there
When you talk to SSB, they don't even know there is another sideband.
Jim VE3DDY
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WU2D
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CW is just a narrower version of AM


« Reply #44 on: August 27, 2011, 07:53:54 PM »

With folks listening hard and using good antennas, and by restricting the QRP Net to Fall-Spring and avoiding the QRN and then loading the bases by optimizing the time to the late Sunday afternoon before sunset so short hop works well, and picking a frequency below the AM window, IT SIMPLY WORKS.
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« Reply #45 on: August 27, 2011, 08:38:42 PM »



I've a hard time telling the difference between slopbucket and noise. Tongue

73DG





There's a difference?
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K5UJ
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« Reply #46 on: August 27, 2011, 10:05:02 PM »

Let Us Now Praise Famous Strappers


Breaking news:  Scholars of the Dead Sea Scrolls have pieced together an extension of
Ecclesiasticus chapter 44, unknown before now.  It appears to be in praise of famous 
strappers according to what can be gathered from the ancient texts:

Let us now praise famous strappers and the radio fathers of the ancient knowledge before us.

They had great glory through great power from the beginning of Eimac.

Such as did bear rule on the bands, men renowned for their class C power, giving counsel by     
their vast knowledge of the ancient circuits and declaring future inventions:

Leaders of the noobs and piss weakers by their counsels, and by their knowledge of learning       
meet for the AMers stuck on city lots, wise and eloquent are their instructions:

Such as found out the angel music of AM, and recited the laws of impedance ratios in writing:

Poor hams furnished with homebrewing ability, living peaceably on the low bands:

All these were honored in their generations, and were the glory of their times.

There be of them, that have left a nickname behind them, that their praises might be reported     
in ER.

And some there be, which have no memorial; their QSL cards perished, as though they were
printed on cheap paper and had never been; and are become as though they never modulated with     
1.5 times their carrier power.

But these were merciful strappers, whose high dipoles hath not been forgotten.

With their knowledge shall continually remain a good inheritance, and their Novices are
within the AM community.

Their keys and microphones are silent in peace but their name liveth for evermore.

The slopbuckets will tell of their wisdom, and the AM community will shew forth their praise.
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Patrick J. / KD5OEI
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« Reply #47 on: August 27, 2011, 11:54:56 PM »

Those ham radio articles harping on 100 watts  - well OK it works fine for SSB much of the time but a bit more is needed to do the same on AM. The articles may have been focusing on the lowest common denominator not the classical modes.

100 Watts is very doable.  One has to choose band and time to operate.  A LOT OF US in here use 100 Watt rigs.  Oh wait, you're comparing apples and oranges.  100 watts "SSB" is P.E.P.  100 watts AM is carrier.... or do you mean 25 watts carrier and 100% modulation?

Yes I mean the 100W PEP, is fine for SSB, but a 100W PEP AM signal (25W carrier if that is so), like comes out of a typical ham transceiver in QST, is more challenging for AM. I meant that the people that wrote it might have disregarded AM. Sorry for the confusion, I have not seen more than 1 or 2 of the articles so I don't know, only speculating their reasons.
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Radio Candelstein - Flagship Station of the NRK Radio Network.
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« Reply #48 on: August 28, 2011, 12:18:05 AM »

I currently run a Yaesu FT-897D on HF. It's a 100W SSB radio, with 25W AM carrier. I've talked to wondrous places far away on slopbucket, but an attempt to talk 20 miles on 160 meter AM met with failure. Admittedly, the antennas on both ends were, uh, less than optimum. We've yet to try on another band -- still due to antenna issues, but I'm really working to get the DX-100 on the air and have some sort of reasonable power on AM. Given the QRM/QRN conditions here in TX, I'm not really optimistic about the chances for QRP AM. However, it may work in some locations or with better antennae than I've got.

ldb
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kg8lb
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« Reply #49 on: August 28, 2011, 07:44:02 AM »

 Roy, K8VWX just checked in to the DX-60 net using his new Retro 75 2 watt rig. Received fine signal reports all around. We flipped the switch and went over to the Retro 75 here worked Columbiana ti Detroit FB . QRM from the Magnolia net and the QRN were no problem. Roy usually runs his pair of 4-1000 mod by 4-1000s and seems to be enjoying the QRP after all these years.
Congrats to Roy !
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