Pages: 1 2 [3] 4   Go Down

Author Topic: QRP With Indoor Antenna  (Read 1717 times)

KB1GMX

  • Member
  • Posts: 2252
Re: QRP With Indoor Antenna
« Reply #30 on: March 21, 2021, 12:14:09 PM »

Ah but ther eis!

 The K0S Strange Antenna Challenge  Memorial day weekend.

Rules are simple and use an antenna NOT using traditional
antenna materials.

Purpose if any, is to prove in an emergency anything
conductive can be a a potential antenna.

One year I loaded up two lounge style lawn chairs  end
to end on the plastic plant pots.  Loaded very well on 17/15
and 10.  A pair of aluminum crutches has been seen as a
wide band dipole.  People have used cars, trucks, tractors as in
many different from little to huge, Chainlink fence (while in use
as a fence and anything else that is possible to imagine. 
Its a way to have fun.

Standard wire in the attic, doesn't qualify.  The heating and
cooling ducts up there would!

One person added  another rule to my three.. 
It was inspired by rule 3 being, any antenna will be
better than a bucket of wire in the garage.
4). You lack imagination, anything can be an antenna.
I guess he took than to mean only wire!


Allison
Logged

KM1H

  • Member
  • Posts: 11155
Re: QRP With Indoor Antenna
« Reply #31 on: March 21, 2021, 05:44:31 PM »

In the AM days the Johnson Viking I and II were well known for loading up bed springs and making plenty of QSO's. Their tank coil was a variable inductor and could load into almost anything.

A lot of this was during Cycle 19 where even 10M was often open 24/7

Carl
Logged

K3UIM

  • Member
  • Posts: 2145
Re: QRP With Indoor Antenna
« Reply #32 on: March 22, 2021, 09:30:51 AM »

Uh, for those not "in the know", bed springs were used "in my day" for antennas for our crystal sets. Today you just might get a whole bunch of QRM from the lady of the house if you're found ripping the box spring covers off to get a connection for the rig. For the sake of a lasting marriage, DON'T DO IT!
And for those of who may be wondering, I threw a dipole up outside, thus the 68 years of her putting up with my antics!!!
Charlie
Logged
Charlie. K3UIM
Where you are: I was!
Where I am: You will be!
So be nice to us old fogies!!

KB9BVN

  • Member
  • Posts: 184
Re: QRP With Indoor Antenna
« Reply #33 on: March 22, 2021, 10:18:08 AM »

One year at Dayton, probably late 1990's early 2000...Roy Griggson was there selling his ZM-2 Z-match antenna tuner kits and he used his tuner to load match a dipole made from two SCHOOL BUSES and made a QSO with that setup. I bought one of his kits and I still use that tuner from time to time. 
Logged

IW5CWC

  • Posts: 63
    • HomeURL
Re: QRP With Indoor Antenna
« Reply #34 on: August 01, 2021, 05:11:31 AM »

My home made indoor magloop 40 -10m works OK.Good results with only 10W.Eu no problem at all,sometimes far DX happens.


Another nice magloop
https://en.hqmagnetic.com/


.


 :)
Andy
http://www.qsl.net/sp9hzx

Sorry for quoting an old post, your indoor loop seems great. Any description or direction to build a similar antenna? That would be a nice alternative to take my scooter and drive onto some hill to deploy my end fed wire on a tree and use the FT818 (since I don't have any shack at home)
Thanks a lot
Logged

N8NK

  • Posts: 179
    • N8NK QRP
Re: QRP With Indoor Antenna
« Reply #35 on: August 01, 2021, 06:44:22 AM »

Not well at all if your house has a metal roof and aluminum foil backed wall insulation.  A pretty decent Faraday Cage at HF frequencies.  ::)
Metal roof? Do they live in houses or sheds down South? ::)

I'm in Michigan and  bought this house specifically because it has a steel roof. Many do here if you can afford them.
Me?
Shucks, i just sell them chickens and rabbits for the folkin to skin, and when a yard bird gets cantankery and flies onto the roof- his poo slides right off in the rain and into buckets. Also, the goats don't like walkin' on metal like they do asphalt shingles.

I've made a contact with Argentina using 2.5 milliwatts and got an S7.
I've made a contact with OL725PLZ using a 2' high dipole.
I've worked DX using a wire laying on my deck, 8" above the soil.

I've done every kind of compromise antenna experiment you can imagine, and it's all on youtube at 'N8NK QRP' if you want to see.
Now back to them chickens. They're pecking away at my 'tin roof'. Better get my fambly together for a chicken roundup. That's 'those people' do.. people with (gasp) metal roofs.
Chuck, N8NK
Logged

N4KZ

  • Member
  • Posts: 761
Re: QRP With Indoor Antenna
« Reply #36 on: August 01, 2021, 08:37:11 AM »

QRP contacts with an indoor antenna are possible. I am blessed to have a tower with a multi-band beam on it but I like QRP CW and decided one day to conduct an experiment. I set up my Yaesu FT-817 with a Miracle Whip antenna on my kitchen table. The Miracle Whip might sound like a salad dressing but it's not. It's a 5-foot long telescopic whip with a matching device at the bottom. I attached it to the back of the FT-817 and connected one 16-foot radial which I connected to the back of the rig. I tuned the matching device to peak signals on receive and began tuning 20 meter CW. I quickly worked an EA8 station plus a G station in the UK. Reports were 449 and 559 but made fairly easily. I have a hilltop QTH so the good take-off I have to the east didn't hurt. I got lucky that day with two quick and easy QSOs but I'm sure I could be successful again with that set-up. Try indoor QRP. You might be surprised. 73, N4KZ   
Logged

SP9HZX

  • Member
  • Posts: 49
    • homeURL
Re: QRP With Indoor Antenna
« Reply #37 on: August 01, 2021, 10:49:43 AM »

My home made indoor magloop 40 -10m works OK.Good results with only 10W.Eu no problem at all,sometimes far DX happens.


Another nice magloop
https://en.hqmagnetic.com/


.


 :)
Andy
http://www.qsl.net/sp9hzx

Sorry for quoting an old post, your indoor loop seems great. Any description or direction to build a similar antenna? That would be a nice alternative to take my scooter and drive onto some hill to deploy my end fed wire on a tree and use the FT818 (since I don't have any shack at home)
Thanks a lot

Motorized Variable Air Capacitor 2 x 4pF - 120pF/600V and 12V tuning motor installed within water-proof box
The Main Loop dia 69cm (RG213 - coax lenght is 2170 mm )
The Coupling Loop dia 19cm (4mm copper wire)
The feeder RG58
Control unit with 2 push buttons (increase/decrease) and a speed control knob
Total weight: +/- 1kg









Recently working from the garden,the antenna on the tripod,I've done easily some PY,JA andZS.
« Last Edit: August 01, 2021, 10:53:27 AM by SP9HZX »
Logged

K0UA

  • Member
  • Posts: 9589
Re: QRP With Indoor Antenna
« Reply #38 on: August 01, 2021, 01:16:45 PM »

All of this strikes to the heart of the OP original question about QRP with an indoor antenna should be classified as QRPP.  Well it isn't, but it should be. The concept that QRP is operation with 5 watts output from the rig is STUPID at best. a 5 watt rig into a 6 over 6 over 6 on a huge tower on 20 meters is HARDLY QRP even though the rules say so. QRP should be 5 watts ERP and down. If you have 13 dB of antenna gain how is that QRP? It doesn't make sense. A guy with a 20 meter vertical in his backyard and a 500 watt amp and lousy radials may have less signal than the QRP enthusiast with his aforementioned stacked array on the big tower quite possibly ? Yet the guy with the big array will be perfectly legal showing his classification as QRP and the guy with the vertical and 500 watt amp won't be.  And yes the guy with a 5 watt rig and an indoor antenna may actually have less signal than a QRPP milliwat guy using that stacked array. We are not so stupid we can't classify our station in terms of ERP instead of output power.  It is all rather academic anyway as propagation can sometimes make more difference than all the stacked arrays and power amps in the real world.

Here is a real world example from yesterday.  FS/W8HC in Saint Martin was on 6 meters yesterday afternoon. I called him for almost an hour with near 700 watts with no results. My competition buddy called him with 1000. No joy. Then my buddy upped the amp to 1.5kw. He got him with a lousy -16 report, but he got him.  2 hours later I awoke from a nap and saw him spotted on 50.323. I had turned the amp off, but did start the exciter calling him with 27 watts. We completed and he gave me a 00 signal report. He was +18 to me by that time.  I cannot really explain that except that propagation is strange.
Logged
73  James K0UA

AE5X

  • Member
  • Posts: 1755
Re: QRP With Indoor Antenna
« Reply #39 on: August 02, 2021, 07:56:35 AM »

Backordered for a long time awaiting parts, AFL Antennas began taking orders for the HF-319 yesterday evening:
http://doxytronics.com/8020ca-portable-hf-magnetic-loop-antenna/

It is highly reviewed and (I think) the most inexpensive of this type on the market.
Logged

WB6BYU

  • Member
  • Posts: 20896
    • Practical Antennas
Re: QRP With Indoor Antenna
« Reply #40 on: August 02, 2021, 12:42:40 PM »

Quote from: K0UA

...a 5 watt rig into a 6 over 6 over 6 on a huge tower on 20 meters is HARDLY QRP even though the rules say so...



(my bold)


Rules?  What rules?  Certainly nothing in Part 97.

If you are entering a contest or making contacts for an award, then,
yes, you follow the rules that are set for that activity.  And if the
sponsor wants to write the rules in terms of ERP, that is their choice.

Otherwise, you can do whatever you want.  It really doesn't matter
if you call it QRP or QRPP.  The first time I entered an ARRL contest,
100 watts was in the QRP category.

And for hams who regularly run at (or above) the legal limit, they
might still consider it QRP, because, for them, it is.

The Q-signal, after all, simply translates to "reduce power".

If I want to turn my rig up from 5 watts to 6 or 10 watts, and I'm
not participating in an activity with specific rules otherwise, then
that isn't a problem.  Or I can turn it down to 2 watts - who cares?
There are no rules that apply.

(My older rigs couldn't run more than about 3W anyway.)


Personally, one of the things that I find satisfying about running
low power is that it emphasizes antenna effectiveness.  I see
hams talking about what a wonderful antenna some mediocre
product is because they made a contact with it running 100W,
when I've done as well with 3 watts to a dipole.  As it is, I think
too many hams assume that the answer to their problems is to
run more power, when the real solution is to improve their
antenna.  (Especially with all the carp and other fishy products
that have become more common as marketing takes precedence
over technical competence.)

In the end, we each make of ham radio whatever we want to.
Better antennas will improve performance at whatever power
level we choose to use.  Each of us gets to choose whether we
will enjoy the hobby (and life) more if we improve our antennas,
increase power, or just take it as a challenge to do the best we can
with what we have.  There are no rules for that, beyond the limits
set in Part 97.

IW5CWC

  • Posts: 63
    • HomeURL
Re: QRP With Indoor Antenna
« Reply #41 on: August 03, 2021, 09:50:24 AM »

My home made indoor magloop 40 -10m works OK.Good results with only 10W.Eu no problem at all,sometimes far DX happens.


Another nice magloop
https://en.hqmagnetic.com/


.


 :)
Andy
http://www.qsl.net/sp9hzx

Sorry for quoting an old post, your indoor loop seems great. Any description or direction to build a similar antenna? That would be a nice alternative to take my scooter and drive onto some hill to deploy my end fed wire on a tree and use the FT818 (since I don't have any shack at home)
Thanks a lot

Motorized Variable Air Capacitor 2 x 4pF - 120pF/600V and 12V tuning motor installed within water-proof box
The Main Loop dia 69cm (RG213 - coax lenght is 2170 mm )
The Coupling Loop dia 19cm (4mm copper wire)
The feeder RG58
Control unit with 2 push buttons (increase/decrease) and a speed control knob
Total weight: +/- 1kg

Recently working from the garden,the antenna on the tripod,I've done easily some PY,JA andZS.

How did you connect the two sections of the capacitor? Parallel to double the capacity?
Thanks
Logged

N6YWU

  • Posts: 362
    • HomeURL
Re: QRP With Indoor Antenna
« Reply #42 on: August 03, 2021, 11:10:52 AM »

Is QRP with an indoor antenna QRPp?

Different people "do" QRP for different reasons, and thus what they call QRP will be different.

Some people do QRP as an operating technique or propagation challenge, thus adding either a big linear or a big antenna sort of defeats how far one can go on a fixed limited ERP.

Some people do QRP for budget reasons (can't afford that big ranch on a hilltop far from QRM).  They don't want to have to compare themselves (in their minds) against someone who operates at 5W after flying their private jet to their island resort QTH and putting a few attenuators on their wall of Collins, Flex, and Elecraft (etc.) equipment.  If the antenna (or land dedicated to it) costs more than the radio, it doesn't count as the same playing field.

Some people do QRP as a fitness challenge.  If you can't carry your QRP rig and antenna a mile or so, then you might as well turn up that big linear near its 220 panel; it's not "real" QRP.  But if you can hoist those dipole wires near the very tops of some 200' trees on a mountainside, all is good.

Some do QRP for contest scores, awards, or miles/mW.  It the rules for one of those don't restrict antenna gain, then the bigger the tower(s) the better.

Then there are rumored to be a few who enter QRP contest or award categories after not looking at their power meter too carefully, or at all (or any smoke coming out of it).

Takes all kinds.
Logged

N1IG

  • Posts: 102
    • HomeURL
Re: QRP With Indoor Antenna
« Reply #43 on: August 03, 2021, 03:49:11 PM »

I thought that "qrpp" meant under 1 watt... 
Logged

N6YWU

  • Posts: 362
    • HomeURL
Re: QRP With Indoor Antenna
« Reply #44 on: August 04, 2021, 06:15:21 AM »

I thought that "qrpp" meant under 1 watt... 

The question seems to be about how one gets to 1 Watt or less of what measurement?

Build a QRPp transmitter that maxes out at less than 1 Watt?   
Turn down the output power on your 5W or 100W transmitter till its meter indicates under 1W?
Leave the power up full, but reduce the peak-to-peak swing of the input into a 5W or 100W amplifier until its output shows less than 1W?
Switch a step attenuator on the output of your 5W QRP rig till a Wattmeter on the output shows less than 1W? 
Use a QRP rig with a long feedline that has 10 dB of loss? 
Use a QRP rig with a (small, low, indoor, etc.) antenna that radiates with less than 10% the efficiency of a half-wave dipole?
Crank up that 1 kW linear into an extremely well shielded dummy load?

All of the above might end up putting out a signal with a measurably identical ERP into the RF far field.
Logged
Pages: 1 2 [3] 4   Go Up