View Full Version : Choice of antenna for the "Tiny Tornado"

04-15-2006, 04:21 PM
I am planning on homebrewing the Tiny Tornado . I have not chosen if it will be for 30 or 40m yet . So, what would be a good antenna for this ? I would like something to be as small as possible and can be erected in minutes for portable use. I was thinking maybe just a wire antenna of some sort. If you have built one of these . What antenna are you using ? 73, Sam

04-15-2006, 07:21 PM
Hello Sam

first off
i do not know how much experience you have

so will act as though
you do not have any HF experience

bare bones rock bound qrpp rigs

are not for ops that are
just starting out on hf
they are easy to build
but # you may spend weeks
between contacts

if you allready have a 50 or 100 watt HF rig
the Tiny Tornado would be fun to build
and put on the air
if you are planing
on this rig beeing your starter hf rig

take it from a old hand at running qrp and qrpp

i beg you on bended knee, do no do it

new hf ops
should start out running at least 10 watts
50 watts is better, 100 watts is much better

as to your question

what kind of antenna
the same kind of antenna you would use
with any other 30 or 40 meter rig

some op like one style antenna
other ops like some other style antenna

do you have any antenna books
the ARRL antenna book
from the 50's and 60's is worth its weight in gold
shows you how to build all kinds of antennas

The Radio Amateur's Handbook
from the 50's,60's and 70's also has lots of antenna info

you can often find
used copies for not much money

check www.abebooks.com and www.albris.com

for field work/hiking camping with a qrp rig

ive use very light weight home made dipoles
using very small gage insulated wire for the
antenna and feed line

most of the time just take along
few hundred feet of small gage insulated wire
and make up something in the field
bring a very small light weight home brew tuner

in the field
40 meters 75 ft of end fed wire
in the trees
always works better
than a minature store bought
antenna costing $80 or more

there is also information on the qrp web sites about
making and using antennas in the field

good luck
yours truly
Mac w8znx

04-15-2006, 08:00 PM
I have to agree with Mac. You will not be happy, if this is your first rig. You need patience and experience to make it work.

I have a PixieII which is the same design. I put mine on 30m and I've made exactly one contact. My antenna is a G5RV Jr. (40m version). I must tell you that my experience is not typical, though. I don't get to operate much. I took me about 2 months to get that one contact and I haven't used it since on the air. I've been working on improving it some.

The Pixie2/Tiny Tornado is a very simple direct conversion receiver. The mixer uses the final amplifier as a simple switching mixer and does not provide any mixer gain. The actual noise figure is about -12dB, which isn't too good, but is good enough to hear and make contacts. All receiver gain is achieved with from the LM386 amplifier which is limited to 46dB (200) in the configuration used in these transceivers. There is a modification that can increase the gain to 74dB. If you want this modification, I will send you a link on your request.

To achieve my contact, I employed a tunable audio filter (Autek QF-1A). This enabled me to decrease the receiver bandwidth and pick out the station I wanted work more easily. There are some great audio filters that can be used to achieve this added selectivity, which by the way also increases your sensitivity by 3dB as well.

For true portable operation, I would select an end feed wire of 1/2w length. You will need a tuner with this type of antenna, but the performance will be good and it will go up into a tree or other support in minutes with minimum trouble.

I hope you find the comments you have received useful. If there is anything else that I can do, let me know.


04-15-2006, 11:34 PM
My HF rig that I have been using for some time now is the Yaesu FT-920 along with a Heahtkit SB-220 and a Cushcraft R6000. I thought the Tiny Tornado would be fun to build and see just how many contacts I could make from something so little and inside an "Altoids" can . You all have giving me some great advice and insight on this . If it is fairly difficult to make regular contacts . Then I think I'll homebrew something that I could get more use out of . I know it may take calling CQ a lot more . But, on the other hand if I could make contacts on a regular basis, then I would still want to try this . 73, Sam

04-16-2006, 07:16 PM
Hi Sam

FT-920 and SB-220 great choice for a hf lash up

#qrp and qrpp rigs can be fun
have built the Small Wonder DSW
and the Red Hot Radio NorCal 20
a few tuna tins, and lots of
50's style novice transmitters

for qrp and qrpp cw
mostly hang out on 80 and 40

when running qrpp less than one watt
it can often be very hard to make
a contact on these bands

fixed station antenna here is a full wave loop
high leg at 70 ft, its a great antenna

best miliwatt dx on 80 is about 375 miles
i was running 100 mw
this was a skeg contact
only call and rst report contact
op on other end had to work
to pull me out of the crud

my first hb qrpp transmitter
about 750 mw output

first night running the rig on 40
made 3 nice contacts
next few nights
made 4 more contacts on 80

then my luck ran out
could not make a contact
nobody heard me for two weeks

its much much
easer running 2 or 3 or 5 watts

camping hiking
i have been using
the Small Wonder DSW
get about 4 watts out of her
build in keyer, vfo, audio freq readout
nice receiver section

this past summer went sail camping
in a little raceing dinghy
sail from place to place then camp
on shore each night
took along a Icom IC-703
big mistake
rig is too dam big and heavy
sucks too much juce
can't realy run it in the dark
like you can a simple mono band xceiver

won't be taking the IC-703 camping agn

have a soft spot in my heart
for Kits made by Dave Benson's
Small Wonder Labs

home/fixed station qrp or qrpp

you could build a home brew transmitter
and use the FT-920 to receive
this is another cheap and easy
way to get on qrp/qrpp

yours truly

04-16-2006, 08:27 PM
Me agn

Sam i have been looking at
the " Stand Alone QRP Transmitter Kit "

its made and sold by
Steve melt solder Weber KD1JV

looks like would be a fun fixed station
qrp/qrpp transmitter

it would be great hooked
up to a old receiver or
could use your FT-920 as a receiver

or you could build one of the Ten Tec
DC receivers kit price is only about $35
to run with it

the transmitter
pwr out varable 0 to 4 watts
built in keyer
receiver hook up
qsk circuit mute relay
pto tuned

it's a mono bander
pick 80,40,30,or 20 meters
kit price $45

prob is there are
lots and lots and lots
of great
qrp/qrpp kits out there
from watt meters to psk monoband xceivers
to multi band cw/ssb xceivers
many come from the USA
some come from the UK
and there are
some very intresting qrp kits from Germany

and a few bum jobs
just me but think the best bare bones
qrp kit is the Small Wonder Rock Mite

but if you have any cash you can do
much better

i enjoy playing around with crystal control
rigs but in the end they are very limited
Tiny Tornado and the Pixi, have bum receivers

Rock Mite is better but
you are stuch on one freq
you are camping in North Ontario
have a few min to play radio
before you go to sleep
turn on your rock bound rig
and find that the frq is in use
20 min later they are still rag chewing
you say the heck with it and turn the rig off

if you have vfo control you can move
fined a clear freq to call cq
or look around for another op that is calling cq
i would not go back to beeing rock bound
in the field
at home i have lots of rocks can switch
rocks to move away from qrm
with most of the little qrp/qrpp rock bound
rigs the crystal is soldered to the board
you are stuck

you can check the E ham reviews
to get a idea how much ops like or do not like
the radios

been playing around with qrp rigs for over
35 years and love it
but nothing like being able to run qro
when you just want to play
and conditions are not so hot

cul Mac

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