So, if I buy it now using website, would I have to pay customs too?? What will be the approximate custom charges. Also =you don't have any local indian place from where it can be dispatched so that the custom charges are saved? Regards
|
Airpal Dual Band SSB TCVR Kit Available
The Airpal SSB Transceiver is finally available,
Highlights of Airpal.on
1. Dual Band 20mt/40mt ssb tcvr
2, RF Output 20MT? 2 watts .
3 RF output 40 MT?? 5 to 7 Watts
4. Designs Bi directional?
5. Expandable to 40 watts
6. Enclosure to be available with option to install a linear and a auto ant tuner.
if you have been waiting the Airpal 20/40MT dual band tcvr then the wait is over.
We have started with a limited quantity of kits to understand the mood of current situation as presently a large number of hams are wishing to use ready made equipment. The quantity is only 25 Kits which are kitted as present. Only packing is taking place now.
I will be adding some you tube video soon with some details on construction. In fact anyone building this kit could do the same and even better then what i could do .
The interesting thing about Airpal is that by next month we will have a enclosure in which you could? mount a linear amp 40 watts linear and an auto tuner.
Thanks for paying attention and here is link to purchase the Airpal.
Thanks and best of 73s
Sunil VU3SUA
|
Re: two radios and one antenna tuner and antenna
#ubitx-v6
One. If you have made the diode modification that I recommended so many years ago to protect Q 90, in early versions this isn¡¯t much of an issue. ?Otherwise yes, you might will blow something. Because you will eventually blow that transistor if it remains unprotected I haven¡¯t looked at the schematics of the later versions so I don¡¯t know what¡¯s going on there. ?The original design acted like a RF power supply to reverse bias the base emitter junction and eventually blow it. ? Anytime you have a diode and what turns out to be a ¡°power supply ¡°there is a requirement for a certain reverse voltage capability. ?If there¡¯s a capacitor in series with a diode you have built a power supply! Think about it
Two. ?At our emergency operation center we have three HF transceivers connected with a single coax switch to our output system. ? There are different varieties of coax which is, some with better isolation than others, we have done fine but you might wish to get one that grounds the unused ports.?
Gordon Kx4z?
toggle quoted message
Show quoted text
On Mar 28, 2023, at 22:27, Richard Spohn <wb2gxm@...> wrote:
?
I avoid possible radio damage by using a bnc patchbay instead of switches. Bnc connectors are much quicker and more convenient to use than most other types of rf connectors such as pl259s-so239s. -- Rich WB2GXM Hi
Now that I have the ubitx 6 working great I would like to connect it to my antenna tuner and then to the antenna as a second radio. I want to be able to use the Icom or ubitx (but only one at a time)? without having to plug and unplug cables all the time.
I have seen several youtube videos saying that you can usually hook two radios to a coax switch with one outgoing cable to the antenna tuner and then antenna.
The videos talk about isolation between the ports and suggest that there is enough isolation to avoid radio damage. I dont see anyone reporting radio damage.
Has anyone hooked a ubitx v6 to a coax switch and run a 100 watt radio thru the other port without damaging the ubitx v6 ?
Would hate to brick the ubitx just for convenient hookup !
thanks
David W9PH
|
Re: two radios and one antenna tuner and antenna
#ubitx-v6
I avoid possible radio damage by using a bnc patchbay instead of switches. Bnc connectors are much quicker and more convenient to use than most other types of rf connectors such as pl259s-so239s. -- Rich WB2GXM
------ Original message------ From: splat1956 Date: Tue, Mar 28, 2023 4:19 PM Cc: Subject:[BITX20] two radios and one antenna tuner and antenna #ubitx-v6
Hi Now that I have the ubitx 6 working great I would like to connect it to my antenna tuner and then to the antenna as a second radio. I want to be able to use the Icom or ubitx (but only one at a time)? without having to plug and unplug cables all the time. I have seen several youtube videos saying that you can usually hook two radios to a coax switch with one outgoing cable to the antenna tuner and then antenna. The videos talk about isolation between the ports and suggest that there is enough isolation to avoid radio damage. I dont see anyone reporting radio damage. Has anyone hooked a ubitx v6 to a coax switch and run a 100 watt radio thru the other port without damaging the ubitx v6 ? Would hate to brick the ubitx just for convenient hookup ! thanks David W9PH
|
Ben, When are you planning to be in India?
Hf Signals is now a USA company. It has no sales in?India as of now. This was a decision arrived at after an agonising debate. The reasons include the taxation policies of se?ling in India and abroad simultaneously from India, complicated snd unclear laws governing production of radio kits. This unfortunate as the original aim of bitx was to provide low cost radios to Indian hams. - f
Hi, I wanted to know about what is the cost of ubitx in indian rupees. And If by any chance I am travelling to Hyderabad, where can I get it? Regards.?
|
Hf Signals is now a USA company. It has no sales in?India as of now. This was a decision arrived at after an agonising debate. The reasons include the taxation policies of se?ling in India and abroad simultaneously from India, complicated snd unclear laws governing production of radio kits. This unfortunate as the original aim of bitx was to provide low cost radios to Indian hams. - f
Hi, I wanted to know about what is the cost of ubitx in indian rupees. And If by any chance I am travelling to Hyderabad, where can I get it? Regards.?
|
two radios and one antenna tuner and antenna
#ubitx-v6
Hi
Now that I have the ubitx 6 working great I would like to connect it to my antenna tuner and then to the antenna as a second radio. I want to be able to use the Icom or ubitx (but only one at a time)? without having to plug and unplug cables all the time.
I have seen several youtube videos saying that you can usually hook two radios to a coax switch with one outgoing cable to the antenna tuner and then antenna.
The videos talk about isolation between the ports and suggest that there is enough isolation to avoid radio damage. I dont see anyone reporting radio damage.
Has anyone hooked a ubitx v6 to a coax switch and run a 100 watt radio thru the other port without damaging the ubitx v6 ?
Would hate to brick the ubitx just for convenient hookup !
thanks
David W9PH
|
So to clarify for the uninitiated (please correct me if i am wrong):
to get the ubitx 6.1 to increment frequency by .1 you turn the tuning knob to the next indent.
To go up by .05 you turn the tuning knob to between indents. This is normal behavior.
Thanks
David
|
Hi, I wanted to know about what is the cost of ubitx in indian rupees. And If by any chance I am travelling to Hyderabad, where can I get it? Regards.?
|
Re: Another new V6 for Me!
Rolan - TNX, I'll check it out.
73,
Justin B.
KI5GKD
|
You are right.? You can only direct enter the frequency to the nearest Khz.? Beyond that you have to tune with the encoder knob.? ?
The keypad frequency entry is in the enterFreq function in the?ubitx_ui.cpp file in the source code.? It could possibly be modified to allow entry down to 10 Hz.
The increments for the tuning knob are hard coded in the doTuning function in the?ubitx_v6.1_code.ino source code file, and could also be modified for finer tuning.
The RIT tuning is set in the doRIT function, and it is currently coded for 0.1 increment.??
|
Re: Easy 20 Watts with any qrp
#bitx40
I also had SSB/CW QSOs with the uBITX 3 and am waiting for some parts to finish my uSDX. Fun to work with QRP although I also have a G2DAF exciter and G2DAF linear, both home brewed built a long time ago apart from some other commercial equipment. Enjoy whatever you like and make the most?of it Regards to all
Lawrence
On Tue, Mar 28, 2023 at 3:31?PM Lawrence Galea via <9h1avlaw= [email protected]> wrote:
Awesome 24000km record QRP QSO to VK4KA
Sorry...let's try this again. I hate working on a phone.
Dan - I live on a sail boat. A couple of meters of tinned braid tossed over the side, a shortened 40 meter vertical, and 8 Watts from my uBITX V6 is all I need for a reliable Winlink connection across the Gulf of Mexico to Brownsville, TX for email and wind data. I know for a fact that I don't "need" 20W or even your suggested 50 W to do what I need to get done.
No sir - everybody does not "need" 50 or more Watts.? You do you - enjoy your QRO gear!?
There is no "reason" to build our own gear? There is no "reason" for the Amateur service either, I guess. That's not going to stop me from building, or continuing to learn how to build amplifiers. That's precisely why I got this ticket, after all.
Best, Andy, KG5RKP/MM
On Sat, Mar 25, 2023 at 01:55 PM, Dan Eggers N7DE wrote:
20 w is -7 dB, and that is too far down.? it is getting close to -10 dB down.? You need to be at 50 w, and that is only -3 dB down.? What I have used for low cost has been an MRF455 in an EB63A board from Communications Concepts, and it works very well.
?
However, the Chinese are selling a 100-w amplifier with a heatsink that has had the level set, and they also sell a lowpass filter board XDT LPF200 for 3 - 30 MHz at a reasonable price that works very well, so these days there really isn't any reason to "build your own" amplifier.?
?
The main thing I am saying is that you need more power so that you can be heard.? I went through enough Electrical Engineering courses that I am now an Electrical Engineer, but I do not think I am going to try design amplifiers from scratch myself.
?
I am very grateful for all of the people who helped produce the UBITX 6, because I think that has been the only low cost real general coverage transceiver that is out there.? ? ? ? ? ? ?73, Dan, N7DE
?
Hi Ted
Thanks. Incidentally the FET is? IRFP150? And Not IRF150 , sorry for the typo.
I will edit at the end of the video..
The FET i have used is Harris IRFP 150
It works great with not much heat at 35 V .
Regards
Sunil vu3sua
|
Re: Easy 20 Watts with any qrp
#bitx40
Awesome 24000km record QRP QSO to VK4KA
Sorry...let's try this again. I hate working on a phone.
Dan - I live on a sail boat. A couple of meters of tinned braid tossed over the side, a shortened 40 meter vertical, and 8 Watts from my uBITX V6 is all I need for a reliable Winlink connection across the Gulf of Mexico to Brownsville, TX for email and wind data. I know for a fact that I don't "need" 20W or even your suggested 50 W to do what I need to get done.
No sir - everybody does not "need" 50 or more Watts.? You do you - enjoy your QRO gear!?
There is no "reason" to build our own gear? There is no "reason" for the Amateur service either, I guess. That's not going to stop me from building, or continuing to learn how to build amplifiers. That's precisely why I got this ticket, after all.
Best, Andy, KG5RKP/MM
On Sat, Mar 25, 2023 at 01:55 PM, Dan Eggers N7DE wrote:
20 w is -7 dB, and that is too far down.? it is getting close to -10 dB down.? You need to be at 50 w, and that is only -3 dB down.? What I have used for low cost has been an MRF455 in an EB63A board from Communications Concepts, and it works very well.
?
However, the Chinese are selling a 100-w amplifier with a heatsink that has had the level set, and they also sell a lowpass filter board XDT LPF200 for 3 - 30 MHz at a reasonable price that works very well, so these days there really isn't any reason to "build your own" amplifier.?
?
The main thing I am saying is that you need more power so that you can be heard.? I went through enough Electrical Engineering courses that I am now an Electrical Engineer, but I do not think I am going to try design amplifiers from scratch myself.
?
I am very grateful for all of the people who helped produce the UBITX 6, because I think that has been the only low cost real general coverage transceiver that is out there.? ? ? ? ? ? ?73, Dan, N7DE
?
Hi Ted
Thanks. Incidentally the FET is? IRFP150? And Not IRF150 , sorry for the typo.
I will edit at the end of the video..
The FET i have used is Harris IRFP 150
It works great with not much heat at 35 V .
Regards
Sunil vu3sua
|
ok a discovery......
Probably not using the correct words but:
If I turn the tuning knob from indent to indent it goes up by .1 but if i leave it between indents (ie between clicks into position) then it goes up by .05.
I knew i was seeing it go past .05 as it moved from .1 to .2 but did not think of leaving it between where it clicked into place. I think this is the solution.
thanks
David W9PH
|
Hi Rolan
Thank you for the reply.
I thought it was incrementing in .05 increments originally but it is clearly going up by .10 increments now.
I dont see anywhere to change this in settings.
Can you direct enter a frequency beyond the decimal point by keypad entry ? I dont see a decimal point and can only add 3846 but can not figure out how to enter 3846.55.
thanks
david
|
Re: Another new V6 for Me!
If you are interested in alternative firmware for the stock v6.1,? I have created my own version on github.? You can check out the features here to see if it is of interest to you:??
https://github.com/rrister/ubitxv6/releases/tag/v6.1
|
I don't know why but I ordered another V6 board - I now have four, this is a sickness... :-\? HF signals must finally have all of the kinks worked out as I cabled it up and immediately had a working radio!? This is the first one that I didn't have to to any alignments to!? :-)
I plan on? leaving this one with the original screen and using a different alternative firmware that does not require a Nextion display.
73,
Justin B.
|
Re: Easy 20 Watts with any qrp
#bitx40
Well, I "paid my dues" in the homebrew department over 50 years
ago.? A world war 2 ARC-5 TVI generator for the PA tube &
socket, an old TV set for its power transformer, plate loading
coil wound on a plastic pill vial, an old auto air filter gave the
perforated metal for the PA tube compartment cover, I'm sure you
get the picture.? I stick to operating these days & let the
younger folks do the design & building.
Gerry Sherman
Sent by the Linux Thunderbird
On 2023-03-28 00:43, Siegfried
Jackstien wrote:
toggle quoted message
Show quoted text
yes .. rs918 is mchf clone
but it was our group that included freedv in mchf and it WAS ME
WHO HAD THE IDEA!!
dg9bfc sigi
Am 28.03.2023 um 00:49 schrieb Gerald
Sherman:
The RS918 is the Chinese copy of M0NKA's McHF.
Gerry Sherman
Sent by the Linux Thunderbird
On 2023-03-27 18:40, Siegfried
Jackstien wrote:
nope .. its the second
first is/was mchf (and now its cloned from china)
i brought david and our programming group together ... rest
is history :-)
the guy with the laptop on very right is me ;-)
i have often used freedv with pc on shortwave and i have
found out that the freedv hardware solution .. smartmic ..
sm1000 .. has an stm32 chip and the mchf also has that stm32
inside ... then i brought david rove in contact of our user
group
dg9bfc sigi
Am 27.03.2023 um 01:35 schrieb
Ashhar Farhan:
The digital voice mode that could possibly
replace ssb is freedv. It is actually two things that work
together.
First, the voice is converted into a
stream of very few bits per second. A usual voice stream
like that of telephone uses about 64,000 bits per
second. Freedv codec reduces it to 700 bits per second.
This is at the cost of reduced quality. However, it is
much better that SSB on 80 meters.
The second thing is an HF modem that can
work at 700 bits per second. This is a weird one. On HF
as signals bounce off the ionosphere and arrive at the
rx antenna, you can have a situation where the same
signal can arrive taking different paths and hence at
different times , overlapping itself. This reduces the
number of times you can rapidly change the frequency of
the signal. This is why FT8 works so well, it is so slow
that fading, et al doesnt affect it. So, what the freedv
modem does is that it transmits a number of parallel ft8
like signals as separate tones within the same audio
which when added up give you higher bandwidth. There is
a very impressive name for it that escapes me now.
Our plan is to add freedv into the sbitx,
making it the the first radio to support it natively.
- f
Gordon:
Either RadComm or Sprat
had an article how students in England were
fascinated by Morse code. When asked why, they
replied that "voice" (SSB) didn't interest them
because they could do that with their cell phone.
But Morse was "better" because their parents
couldn't understand what was being said.
Any port in a storm...
Jack, W8TEE
Well, for several years now we have
observed some thing very fascinating among
middle schoolers in our local school.
They are not interested at all in
walkie-talkies
They are not interested at all in HF
radios
Don¡¯t even get me thinking about
digital.
What they absolutely go crazy over,
what they will grab onto and play with
until you have to pull them away kicking
and screaming with their parents,
Is a Morse code key!!!
At every school open house that we hold
we now always provide multiple Morse code
keys and it is a big draw.
We will provide them at this year¡®s
field day
The news media always want a picture of
someone sending Morse code
We have two 6th graders in a very small
school that are already doing about 10
words per minute. I sent 30 minutes worth
of code to them two weeks ago?
It is astonishing the attraction that
Morse code has for these middle schoolers
Meanwhile, across town, at the school
devoted to future police and fire high
schoolers, they have an extremely active
contesting high school I am radio club and
I am told that their best operator can do
over 30 words per minute and they
routinely make hundreds and hundreds of
contacts at voice and CW in contests. ?
Our local ham radio club would have a
hard time beating them!!!!
So I wouldn¡¯t quite give up yet. ?human
nature is the same. And there are certain
number of us who really love the auditory
and tactile tickling that only Morse code
gives¡. And by the way it is the first
digital, the only digital that can be
decoded by the human brain without much
else.? End it enjoys an order of magnitude
or two advantage over voice In terms of
threshold signal to noise ratio!!!?
On Mar 26, 2023,
at 13:23, Dan Eggers N7DE <N7DE@...>
wrote:
?
Thank
you?for the
information.? I see you and I are both
CW old timers.? So far we have lost
about half of the CW people without any
real replacements coming along, but you
and I came along during a certain era.
Best wishes.? ? ?
?73, Dan
Eventually there will be something that
replaces analog single side band voice.
But it¡¯s not yet here. ? And I think I
have been doing CW for 55 years or more. ?
That¡¯s my thought
Gordon Kx4z?
On Mar 26,
2023, at 11:51, Dan Eggers N7DE <N7DE@...>
wrote:
?
I have
been sending Morse code now for
57 years, and I will just
continue to send Morse code, but
since you seem to be very
knowledgeable is there a digital
voice modulation system that
will eventually replace SSB?
Thank
you.? ? ? ? ? 73, Dan, N7DE?
Single side band typically
requires a 10 DB signal to noise
ratio for useful communications in
a disaster.? That is, the
efficient transfer of information
My contrast, using the same
base noise in that bandwidth,
data communications of moderate
speed can tolerate SNR into low
single digits, and still move
efficient communications far
faster than voice
Low data rate redundant
digital communications can
tolerate signal to noise ratios
a couple orders of magnitude
lower SNR
These comparisons are widely
available
It¡¯s no secret why people who
are very involved in the (voice)
national traffic system often
have kilowatt amplifiers. ?
And people who are into JS8
?don¡¯t need them
So there are different
requirements for different parts
of our hobby
On Mar
26, 2023, at 11:33, Dan
Eggers N7DE <N7DE@...>
wrote:
?
I
used 20 watts for a long
time, and I have had a
number of people refuse
to talk to me, because
my signal was too week,
so more power is
needed.? I have written
a booklet about solar
cells, and maybe you use
solar cells and power
conversion, and that is
also a very interesting
area, but I also want to
be able to talk to
people.
?
? ? 73, Dan, N7DE? ?
With respect, Dan,
"need" isn't an actionable
or useful concept,
especially in QRP land.
I live on a sailboat and
am currently in Tampa Bay.
With a couple of meters of
tinn
On Sat, Mar 25, 2023 at
01:55 PM, Dan Eggers N7DE
wrote:
20 w is -7 dB, and that is too far down.? it is
getting close to -10
dB down.? You need
to be at 50 w, and
that is only -3 dB
down.? What I have
used for low cost
has been an MRF455
in an EB63A board
from Communications
Concepts, and it
works very well.
?
However, the Chinese are selling a 100-w
amplifier with a
heatsink that has
had the level set,
and they also sell a
lowpass filter board
XDT LPF200 for 3 -
30 MHz at a
reasonable price
that works very
well, so these days
there really isn't
any reason to "build
your own"
amplifier.?
?
The main thing I am saying is that you need more
power so that you
can be heard.? I
went through enough
Electrical
Engineering courses
that I am now an
Electrical Engineer,
but I do not think I
am going to try
design amplifiers
from scratch myself.
?
I am very grateful for all of the people who
helped produce the
UBITX 6, because I
think that has been
the only low cost
real general
coverage transceiver
that is out there.?
? ? ? ? ? ?73, Dan,
N7DE
?
Hi Ted
Thanks. Incidentally
the FET is? IRFP150?
And Not IRF150 , sorry
for the typo.
I will edit at the end
of the video..
The FET i have used is
Harris IRFP 150
It works great with
not much heat at 35 V
.
Regards
Sunil vu3sua
--
Jack, W8TEE
|
Re: Easy 20 Watts with any qrp
#bitx40
yes .. rs918 is mchf clone
but it was our group that included freedv in mchf and it WAS ME
WHO HAD THE IDEA!!
dg9bfc sigi
Am 28.03.2023 um 00:49 schrieb Gerald
Sherman:
toggle quoted message
Show quoted text
The RS918 is the Chinese copy of M0NKA's McHF.
Gerry Sherman
Sent by the Linux Thunderbird
On 2023-03-27 18:40, Siegfried
Jackstien wrote:
nope .. its the second
first is/was mchf (and now its cloned from china)
i brought david and our programming group together ... rest
is history :-)
the guy with the laptop on very right is me ;-)
i have often used freedv with pc on shortwave and i have
found out that the freedv hardware solution .. smartmic ..
sm1000 .. has an stm32 chip and the mchf also has that stm32
inside ... then i brought david rove in contact of our user
group
dg9bfc sigi
Am 27.03.2023 um 01:35 schrieb
Ashhar Farhan:
The digital voice mode that could possibly
replace ssb is freedv. It is actually two things that work
together.
First, the voice is converted into a stream
of very few bits per second. A usual voice stream like
that of telephone uses about 64,000 bits per second.
Freedv codec reduces it to 700 bits per second. This is at
the cost of reduced quality. However, it is much better
that SSB on 80 meters.
The second thing is an HF modem that can
work at 700 bits per second. This is a weird one. On HF as
signals bounce off the ionosphere and arrive at the rx
antenna, you can have a situation where the same signal
can arrive taking different paths and hence at different
times , overlapping itself. This reduces the number of
times you can rapidly change the frequency of the signal.
This is why FT8 works so well, it is so slow that fading,
et al doesnt affect it. So, what the freedv modem does is
that it transmits a number of parallel ft8 like signals as
separate tones within the same audio which when added up
give you higher bandwidth. There is a very impressive name
for it that escapes me now.
Our plan is to add freedv into the sbitx,
making it the the first radio to support it natively.
- f
Gordon:
Either RadComm or Sprat had
an article how students in England were fascinated
by Morse code. When asked why, they replied that
"voice" (SSB) didn't interest them because they
could do that with their cell phone. But Morse was
"better" because their parents couldn't understand
what was being said.
Any port in a storm...
Jack, W8TEE
Well, for several years now we have
observed some thing very fascinating among
middle schoolers in our local school.
They are not interested at all in
walkie-talkies
They are not interested at all in HF
radios
Don¡¯t even get me thinking about digital.
What they absolutely go crazy over, what
they will grab onto and play with until you
have to pull them away kicking and screaming
with their parents,
Is a Morse code key!!!
At every school open house that we hold
we now always provide multiple Morse code
keys and it is a big draw.
We will provide them at this year¡®s field
day
The news media always want a picture of
someone sending Morse code
We have two 6th graders in a very small
school that are already doing about 10 words
per minute. I sent 30 minutes worth of code
to them two weeks ago?
It is astonishing the attraction that
Morse code has for these middle schoolers
Meanwhile, across town, at the school
devoted to future police and fire high
schoolers, they have an extremely active
contesting high school I am radio club and I
am told that their best operator can do over
30 words per minute and they routinely make
hundreds and hundreds of contacts at voice
and CW in contests. ?
Our local ham radio club would have a
hard time beating them!!!!
So I wouldn¡¯t quite give up yet. ?human
nature is the same. And there are certain
number of us who really love the auditory
and tactile tickling that only Morse code
gives¡. And by the way it is the first
digital, the only digital that can be
decoded by the human brain without much
else.? End it enjoys an order of magnitude
or two advantage over voice In terms of
threshold signal to noise ratio!!!?
On Mar 26, 2023,
at 13:23, Dan Eggers N7DE <N7DE@...>
wrote:
?
Thank
you?for the
information.? I see you and I are both CW
old timers.? So far we have lost about
half of the CW people without any real
replacements coming along, but you and I
came along during a certain era.
Best wishes.? ? ?
?73, Dan
Eventually there will be something that
replaces analog single side band voice. But
it¡¯s not yet here. ? And I think I have been
doing CW for 55 years or more. ?
That¡¯s my thought
Gordon Kx4z?
On Mar 26, 2023,
at 11:51, Dan Eggers N7DE <N7DE@...>
wrote:
?
I have been
sending Morse code now for 57
years, and I will just continue to
send Morse code, but since you
seem to be very knowledgeable is
there a digital voice modulation
system that will eventually
replace SSB?
Thank you.?
? ? ? ? 73, Dan, N7DE?
Single side band typically requires
a 10 DB signal to noise ratio for
useful communications in a
disaster.? That is, the efficient
transfer of information
My contrast, using the same
base noise in that bandwidth, data
communications of moderate speed
can tolerate SNR into low single
digits, and still move efficient
communications far faster than
voice
Low data rate redundant digital
communications can tolerate signal
to noise ratios a couple orders of
magnitude lower SNR
These comparisons are widely
available
It¡¯s no secret why people who
are very involved in the (voice)
national traffic system often have
kilowatt amplifiers. ?
And people who are into JS8
?don¡¯t need them
So there are different
requirements for different parts
of our hobby
On Mar
26, 2023, at 11:33, Dan Eggers
N7DE <N7DE@...>
wrote:
?
I
used 20 watts for a long
time, and I have had a
number of people refuse to
talk to me, because my
signal was too week, so
more power is needed.? I
have written a booklet
about solar cells, and
maybe you use solar cells
and power conversion, and
that is also a very
interesting area, but I
also want to be able to
talk to people.
? ?
? 73, Dan, N7DE? ?
With respect, Dan, "need"
isn't an actionable or
useful concept, especially
in QRP land.
I live on a sailboat and am
currently in Tampa Bay. With
a couple of meters of tinn
On Sat, Mar 25, 2023 at
01:55 PM, Dan Eggers N7DE
wrote:
20
w is -7 dB, and that
is too far down.? it
is getting close to
-10 dB down.? You need
to be at 50 w, and
that is only -3 dB
down.? What I have
used for low cost has
been an MRF455 in an
EB63A board from
Communications
Concepts, and it works
very well.
?
However,
the Chinese are
selling a 100-w
amplifier with a
heatsink that has had
the level set, and
they also sell a
lowpass filter board
XDT LPF200 for 3 - 30
MHz at a reasonable
price that works very
well, so these days
there really isn't any
reason to "build your
own" amplifier.?
?
The
main thing I am saying
is that you need more
power so that you can
be heard.? I went
through enough
Electrical Engineering
courses that I am now
an Electrical
Engineer, but I do not
think I am going to
try design amplifiers
from scratch myself.
?
I
am very grateful for
all of the people who
helped produce the
UBITX 6, because I
think that has been
the only low cost real
general coverage
transceiver that is
out there.? ? ? ? ? ?
?73, Dan, N7DE
?
Hi Ted
Thanks. Incidentally the
FET is? IRFP150? And Not
IRF150 , sorry for the
typo.
I will edit at the end
of the video..
The FET i have used is
Harris IRFP 150
It works great with not
much heat at 35 V .
Regards
Sunil vu3sua
--
Jack, W8TEE
|
Re: Easy 20 Watts with any qrp
#bitx40
I thought that I could do everything myself when we were working with vacuum tubes, and when transistors came along early on it seemed like you could still do things yourself, but now with integrated circuits
and firmware it is impossible to do everything yourself.? That is why I am grateful for all of you.
? ? ? ? ?73, Dan, N7DE
toggle quoted message
Show quoted text
Sigi,
What a fun way to do it. It is so much more enlightening when you have a bunch of friends to do it with.
?I wish we could dumb down an ssb radio to the point that people with soldering skills could sit down with a bag of parts and solder it up over a few evenings. That was my attempt with the original bitx20. However, we seem to be moving to more
and more complex radios that work less and less transparently.
Yesterday, while trying to debug a pesky problem on the new sbitx, I was cursing myself for not understanding how it works (after working on it for 4 years)...
On Tue, Mar 28, 2023, 4:19 AM Gerald Sherman < ve4gks@...> wrote:
The RS918 is the Chinese copy of M0NKA's McHF.
Gerry Sherman
Sent by the Linux Thunderbird
On 2023-03-27 18:40, Siegfried Jackstien wrote:
nope .. its the second
first is/was mchf (and now its cloned from china)
i brought david and our programming group together ... rest is history :-)
the guy with the laptop on very right is me ;-)
i have often used freedv with pc on shortwave and i have found out that the freedv hardware solution .. smartmic .. sm1000 .. has an stm32 chip and the mchf also has that stm32 inside ... then i brought david rove in contact of our user group
dg9bfc sigi
Am 27.03.2023 um 01:35 schrieb Ashhar Farhan:
The digital voice mode that could possibly replace ssb is freedv. It is actually two things that work together.
First, the voice is converted into a stream of very few bits per second. A usual voice stream like that of telephone uses about 64,000 bits per second. Freedv codec reduces it to 700 bits per second. This is at the cost of reduced quality. However,
it is much better that SSB on 80 meters.
The second thing is an HF modem that can work at 700 bits per second. This is a weird one. On HF as signals bounce off the ionosphere and arrive at the rx antenna, you can have a situation where the same signal can arrive taking different paths
and hence at different times , overlapping itself. This reduces the number of times you can rapidly change the frequency of the signal. This is why FT8 works so well, it is so slow that fading, et al doesnt affect it. So, what the freedv modem does is that
it transmits a number of parallel ft8 like signals as separate tones within the same audio which when added up give you higher bandwidth. There is a very impressive name for it that escapes me now.
Our plan is to add freedv into the sbitx, making it the the first radio to support it natively.
- f
Gordon:
Either RadComm or Sprat had an article how students in England were fascinated by Morse code. When asked why, they replied that "voice" (SSB) didn't interest them because they could do that with their cell phone. But Morse was "better"
because their parents couldn't understand what was being said.
Any port in a storm...
Jack, W8TEE
Well, for several years now we have observed some thing very fascinating among middle schoolers in our local school.
They are not interested at all in walkie-talkies
They are not interested at all in HF radios
Don¡¯t even get me thinking about digital.
What they absolutely go crazy over, what they will grab onto and play with until you have to pull them away kicking and screaming with their parents,
Is a Morse code key!!!
At every school open house that we hold we now always provide multiple Morse code keys and it is a big draw.
We will provide them at this year¡®s field day
The news media always want a picture of someone sending Morse code
We have two 6th graders in a very small school that are already doing about 10 words per minute. I sent 30 minutes worth of code to them two weeks ago?
It is astonishing the attraction that Morse code has for these middle schoolers
Meanwhile, across town, at the school devoted to future police and fire high schoolers, they have an extremely active contesting high school I am radio club and I am told that their best operator can do over 30 words per minute and they routinely make
hundreds and hundreds of contacts at voice and CW in contests. ?
Our local ham radio club would have a hard time beating them!!!!
So I wouldn¡¯t quite give up yet. ?human nature is the same. And there are certain number of us who really love the auditory and tactile tickling that only Morse code gives¡. And by the way it is the first digital, the only digital that can be decoded by
the human brain without much else.? End it enjoys an order of magnitude or two advantage over voice In terms of threshold signal to noise ratio!!!?
On Mar 26, 2023, at 13:23, Dan Eggers N7DE <N7DE@...> wrote:
?
Thank you?for the information.? I see you and I are both CW old timers.? So far we have lost about half of the CW people without any real replacements coming along, but you and I came along during a certain era.
Best wishes.? ? ? ?73, Dan
Eventually there will be something that replaces analog single side band voice. But it¡¯s not yet here. ? And I think I have been doing CW for 55 years or more. ?
That¡¯s my thought
Gordon Kx4z?
On Mar 26, 2023, at 11:51, Dan Eggers N7DE <N7DE@...> wrote:
?
I have been sending Morse code now for 57 years, and I will just continue to send Morse code, but since you seem to be very knowledgeable is there a digital voice modulation system that will eventually replace SSB?
Thank you.? ? ? ? ? 73, Dan, N7DE?
Single side band typically requires a 10 DB signal to noise ratio for useful communications in a disaster.? That is, the efficient transfer of information
My contrast, using the same base noise in that bandwidth, data communications of moderate speed can tolerate SNR into low single digits, and still move efficient communications far faster than voice
Low data rate redundant digital communications can tolerate signal to noise ratios a couple orders of magnitude lower SNR
These comparisons are widely available
It¡¯s no secret why people who are very involved in the (voice) national traffic system often have kilowatt amplifiers. ?
And people who are into JS8 ?don¡¯t need them
So there are different requirements for different parts of our hobby
On Mar 26, 2023, at 11:33, Dan Eggers N7DE <N7DE@...> wrote:
?
I used 20 watts for a long time, and I have had a number of people refuse to talk to me, because my signal was too week, so more power is needed.? I have written a booklet about solar cells, and maybe you use solar cells and power
conversion, and that is also a very interesting area, but I also want to be able to talk to people.
? ? ? 73, Dan, N7DE? ?
With respect, Dan, "need" isn't an actionable or useful concept, especially in QRP land.
I live on a sailboat and am currently in Tampa Bay. With a couple of meters of tinn
On Sat, Mar 25, 2023 at 01:55 PM, Dan Eggers N7DE wrote:
20 w is -7 dB, and that is too far down.? it is getting close to -10 dB down.? You need to be at 50 w, and that is only -3 dB down.? What I have used for low cost has been an MRF455 in an EB63A board from Communications Concepts,
and it works very well.
?
However, the Chinese are selling a 100-w amplifier with a heatsink that has had the level set, and they also sell a lowpass filter board XDT LPF200 for 3 - 30 MHz at a reasonable price that works very well, so these days there really
isn't any reason to "build your own" amplifier.?
?
The main thing I am saying is that you need more power so that you can be heard.? I went through enough Electrical Engineering courses that I am now an Electrical Engineer, but I do not think I am going to try design amplifiers
from scratch myself.
?
I am very grateful for all of the people who helped produce the UBITX 6, because I think that has been the only low cost real general coverage transceiver that is out there.? ? ? ? ? ? ?73, Dan, N7DE
?
Hi Ted
Thanks. Incidentally the FET is? IRFP150? And Not IRF150 , sorry for the typo.
I will edit at the end of the video..
The FET i have used is Harris IRFP 150
It works great with not much heat at 35 V .
Regards
Sunil vu3sua
--
Jack, W8TEE
|
Sunil Lakhani