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Hi,
?
If I am running at 9V, and I am transmitting FT8 at 100%, what output power are you expecting and how much power is the device consuming?
?
Cheers,
Ben
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At 8.4v(Batts) i'm seeing about 5w on tx On Wed, May 7, 2025 at 6:41?PM Ben Sanders via <sandersbenjamin= [email protected]> wrote:
Hi,
?
If I am running at 9V, and I am transmitting FT8 at 100%, what output power are you expecting and how much power is the device consuming?
?
Cheers,
Ben
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Do you happen to know how much power it is drawing then?
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At 9v and 100% I was showing 5 watts out with a current draw of around 3.8 amps on FT-8.
Cheers
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On May 8, 2025, at 4:31?PM, Ben Sanders via groups.io <sandersbenjamin@...> wrote:
Do you happen to know how much power it is drawing then?
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Of course, the output power measurement is just probably by measuring voltage and assuming a resistance, but that’s a pretty low overall calculated efficiency, 15% or so. ? And of course part of that is that it’s having to run the other circuits but they aren’t that high power hogging! Perhaps other than the display? ? wide band transformer systems aren’t anywhere close to as good as the tuned networks we use decades ago. ? At least it seems that way.!!
Gordon kx4z?
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On May 8, 2025, at 17:04, JAMES LEWIS JR via groups.io <jtlewis@...> wrote:
? At 9v and 100% I was showing 5 watts out with a current draw of around 3.8 amps on FT-8.
Cheers
Jim
On May 8, 2025, at 4:31?PM, Ben Sanders via groups.io <sandersbenjamin@...> wrote:
Do you happen to know how much power it is drawing then?
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Thanks!? Just wanted to double check - that's what I was seeing, but seemed high.
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When you talk about efficiency, what are you actually talking about?
When I discuss efficiency I'm talking about a power source - 120 v, 3 amps in, 12 v, 23 amps out, for example.
I've never seen anyone compare radio efficiency - 13.8v at 21 amps in(290 watts) and comparing that to RF output (100 watt), about 34% efficency.
The Ft-818 needed 2.4 amps at 9.6v (23 watts) to generate 6 watts RF, that's about 25% efficiency, based on your model...
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On May 8, 2025, at 17:38, Gordon Gibby KX4Z via groups.io <docvacuumtubes@...> wrote:
? Of course, the output power measurement is just probably by measuring voltage and assuming a resistance, but that’s a pretty low overall calculated efficiency, 15% or so. ? And of course part of that is that it’s having to run the other circuits but they aren’t that high power hogging! Perhaps other than the display? ? wide band transformer systems aren’t anywhere close to as good as the tuned networks we use decades ago. ? At least it seems that way.!!
Gordon kx4z?
On May 8, 2025, at 17:04, JAMES LEWIS JR via groups.io <jtlewis@...> wrote:
? At 9v and 100% I was showing 5 watts out with a current draw of around 3.8 amps on FT-8.
Cheers
Jim
On May 8, 2025, at 4:31?PM, Ben Sanders via groups.io <sandersbenjamin@...> wrote:
Do you happen to know how much power it is drawing then?
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Ken, anybody who’s having to work off batteries thinks this way. ?It’s a very important parameter to them.
I suspect the people who pay the light bill for 50 kW transmitters also think this way; but I don’t know that for sure.
When you’re trying to figure out if you can run that amplifier on that circuit or if you’re going to need to put in a 220 V circuit you think that way also ?
It can be difficult to figure out the actual efficiency of the final stage, but it’s not hard at all to come up with the overall efficiency
It’s one of the things that people in my neck of the woods have complained about some radios!!
Gordon kx4z?
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On May 9, 2025, at 17:51, Ken N2VIP via groups.io <ken@...> wrote:
? When you talk about efficiency, what are you actually talking about?
When I discuss efficiency I'm talking about a power source - 120 v, 3 amps in, 12 v, 23 amps out, for example.
I've never seen anyone compare radio efficiency - 13.8v at 21 amps in(290 watts) and comparing that to RF output (100 watt), about 34% efficency.
The Ft-818 needed 2.4 amps at 9.6v (23 watts) to generate 6 watts RF, that's about 25% efficiency, based on your model... Ken, N2VIP On May 8, 2025, at 17:38, Gordon Gibby KX4Z via groups.io <docvacuumtubes@...> wrote:
? Of course, the output power measurement is just probably by measuring voltage and assuming a resistance, but that’s a pretty low overall calculated efficiency, 15% or so. ? And of course part of that is that it’s having to run the other circuits but they aren’t that high power hogging! Perhaps other than the display? ? wide band transformer systems aren’t anywhere close to as good as the tuned networks we use decades ago. ? At least it seems that way.!!
Gordon kx4z?
On May 8, 2025, at 17:04, JAMES LEWIS JR via groups.io <jtlewis@...> wrote:
? At 9v and 100% I was showing 5 watts out with a current draw of around 3.8 amps on FT-8.
Cheers
Jim
On May 8, 2025, at 4:31?PM, Ben Sanders via groups.io <sandersbenjamin@...> wrote:
Do you happen to know how much power it is drawing then?
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Gordon,
Understood, but you are describing concerns about "power consumption" which just part of the "power efficiency" calculation.
I've heard people talk about consumption all the time, but not couched in terms of "efficiency" per se.
Thanks,
Ken, N2VIP
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On May 9, 2025, at 18:03, Gordon Gibby KX4Z via groups.io <docvacuumtubes@...> wrote:
Ken, anybody who’s having to work off batteries thinks this way. It’s a very important parameter to them.
I suspect the people who pay the light bill for 50 kW transmitters also think this way; but I don’t know that for sure.
When you’re trying to figure out if you can run that amplifier on that circuit or if you’re going to need to put in a 220 V circuit you think that way also
It can be difficult to figure out the actual efficiency of the final stage, but it’s not hard at all to come up with the overall efficiency
It’s one of the things that people in my neck of the woods have complained about some radios!!
Gordon kx4z
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Sorry to change the subject (slightly), but I'd like to know how far outside the specs in the manual we can go with power adapters.? The zbitx manual says 6-9 volts is preferred.? Will a 5V or a 10V supply break the radio? I have both of these, and was wondering which one (if either) I could use on the radio.? Failing that, what kind of setup would I need to attach a 12-volt deep cycle battery (taken from a power scooter) to the radio.? My wife had two of these batteries for her power chair, but it has since stopped working.? I use them directly to power my yaesu 857, and it works just fine, but since that radio doesn't transmit, I'd like to try using them on the zbitx.? Would I need a voltage regulator to reduce power to 6-9 volts, or can it handle the 12 volts directly?
The manual says we need 6-9 volts, with at least 3A for the radio, but I'm hoping there's some wiggle room in there, because I'm hard pressed to find such an adapter already lying around here.? I'll have to go find one on amazon or something, but until then, can I use either of the above mentioned supplies w/o fear of burning up the radio?
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Ooh, did you order one of these?!?
--
Buddy Brannan, KB5ELV, WRVB670?-?Erie, PA
Email: buddy@...
Mobile: (814) 431-0962
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On May 9, 2025, at 6:37?PM, Travis Siegel <tsiegel@...> wrote:
Sorry to change the subject (slightly), but I'd like to know how far outside the specs in the manual we can go with power adapters.? The zbitx manual says 6-9 volts is preferred.? Will a 5V or a 10V supply break the radio? I have both of these, and was wondering which one (if either) I could use on the radio.? Failing that, what kind of setup would I need to attach a 12-volt deep cycle battery (taken from a power scooter) to the radio.? My wife had two of these batteries for her power chair, but it has since stopped working.? I use them directly to power my yaesu 857, and it works just fine, but since that radio doesn't transmit, I'd like to try using them on the zbitx.? Would I need a voltage regulator to reduce power to 6-9 volts, or can it handle the 12 volts directly?
The manual says we need 6-9 volts, with at least 3A for the radio, but I'm hoping there's some wiggle room in there, because I'm hard pressed to find such an adapter already lying around here.? I'll have to go find one on amazon or something, but until then, can I use either of the above mentioned supplies w/o fear of burning up the radio?
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It might be OK with 10 V but it’s so easy to get that down to 9.3 or so that why not? Find yourself four or 5 A worth of silicon diodes (either in one of them or in several in parallel) and use it to drop the voltage from 10 to 9.3!
Then you can feel pretty secure and be using one of the batteries you wanted to use. Let somebody else do the experiments on their radio, I wouldn’t do it on mine. The manufacturer has told you what he’s looking for! He calculated all of the bias points in current based on the voltages he recommended
Those are just my opinions. I’m sure other people will differ.
Gordon kx4z
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On May 9, 2025, at 18:51, Travis Siegel via groups.io <tsiegel@...> wrote:
?Sorry to change the subject (slightly), but I'd like to know how far outside the specs in the manual we can go with power adapters. The zbitx manual says 6-9 volts is preferred. Will a 5V or a 10V supply break the radio? I have both of these, and was wondering which one (if either) I could use on the radio. Failing that, what kind of setup would I need to attach a 12-volt deep cycle battery (taken from a power scooter) to the radio. My wife had two of these batteries for her power chair, but it has since stopped working. I use them directly to power my yaesu 857, and it works just fine, but since that radio doesn't transmit, I'd like to try using them on the zbitx. Would I need a voltage regulator to reduce power to 6-9 volts, or can it handle the 12 volts directly?
The manual says we need 6-9 volts, with at least 3A for the radio, but I'm hoping there's some wiggle room in there, because I'm hard pressed to find such an adapter already lying around here. I'll have to go find one on amazon or something, but until then, can I use either of the above mentioned supplies w/o fear of burning up the radio?
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To be clear: diodes in parallel will lessen the voltage drop, same as with resistors in parallel. Diodes in series will increase the drop, ie one silicon diode will drop the voltage by 0.7v, two will drop the voltage by 1.4v, etc.
On Fri, May 9, 2025, 8:05 PM Gordon Gibby KX4Z via <docvacuumtubes= [email protected]> wrote: It might be OK with 10 V but it’s so easy to get that down to 9.3 or so that why not?? Find yourself four or 5 A worth of silicon diodes (either in one of them or in several in parallel) and use it to drop the voltage from 10 to 9.3!
Then you can feel pretty secure and be using one of the batteries you wanted to use. Let somebody else do the experiments on their radio, I wouldn’t do it on mine. The manufacturer has told you what he’s looking for!? He calculated all of the bias points in current based on the voltages he recommended
Those are just my opinions. I’m sure other people will differ.
Gordon kx4z
> On May 9, 2025, at 18:51, Travis Siegel via <tsiegel=[email protected]> wrote:
>
> ?Sorry to change the subject (slightly), but I'd like to know how far outside the specs in the manual we can go with power adapters.? The zbitx manual says 6-9 volts is preferred.? Will a 5V or a 10V supply break the radio? I have both of these, and was wondering which one (if either) I could use on the radio.? Failing that, what kind of setup would I need to attach a 12-volt deep cycle battery (taken from a power scooter) to the radio.? My wife had two of these batteries for her power chair, but it has since stopped working.? I use them directly to power my yaesu 857, and it works just fine, but since that radio doesn't transmit, I'd like to try using them on the zbitx.? Would I need a voltage regulator to reduce power to 6-9 volts, or can it handle the 12 volts directly?
>
> The manual says we need 6-9 volts, with at least 3A for the radio, but I'm hoping there's some wiggle room in there, because I'm hard pressed to find such an adapter already lying around here.? I'll have to go find one on amazon or something, but until then, can I use either of the above mentioned supplies w/o fear of burning up the radio?
>
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When calculating transmitter power efficiency of a transceiver, on usually subtracts out the idle power requirements of receive mode.
73, Ron, n6ywu
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Thanks, Richard for adding.? ?Certainly diodes in SERIES will drop the voltage by approximately 0.7V each (if silicon diodes)
In parallel, it is a little different because the diodes are NON LINEAR devices and have a very small effective dynamic resistance once they have reached their threshold.? ?So putting 4 or 5 1N4007's together in parallel is still likely to have a total voltage drop of about 0.7V from 1/2 ampere all the way to 3 or 4 amperes, at normal temperatures.? ?At very high temperatures, the voltage drop might be a little less (the opposite of wires).? ??
As you point out, I've used series diodes more than once to protect a device rated at 9V? (a wifi router, for example) from a 14 V source (a lifepo4 battery).
I just dont' think it is worth tempting fate when the designer has put a lot of work into making a piece of equipment and specifies which voltages he designed it for.? ?Biasing circuits are often somewhat voltage dependent, as can be idling currents, and dissipations in regulators.? ?You can TRY running a gasoline engine on Diesel...but not for long!
73 Gordon KX4Z
To be clear: diodes in parallel will lessen the voltage drop, same as with resistors in parallel. Diodes in series will increase the drop, ie one silicon diode will drop the voltage by 0.7v, two will drop the voltage by 1.4v, etc.
On Fri, May 9, 2025, 8:05 PM Gordon Gibby KX4Z via <docvacuumtubes= [email protected]> wrote: It might be OK with 10 V but it’s so easy to get that down to 9.3 or so that why not?? Find yourself four or 5 A worth of silicon diodes (either in one of them or in several in parallel) and use it to drop the voltage from 10 to 9.3!
Then you can feel pretty secure and be using one of the batteries you wanted to use. Let somebody else do the experiments on their radio, I wouldn’t do it on mine. The manufacturer has told you what he’s looking for!? He calculated all of the bias points in current based on the voltages he recommended
Those are just my opinions. I’m sure other people will differ.
Gordon kx4z
> On May 9, 2025, at 18:51, Travis Siegel via <tsiegel=[email protected]> wrote:
>
> ?Sorry to change the subject (slightly), but I'd like to know how far outside the specs in the manual we can go with power adapters.? The zbitx manual says 6-9 volts is preferred.? Will a 5V or a 10V supply break the radio? I have both of these, and was wondering which one (if either) I could use on the radio.? Failing that, what kind of setup would I need to attach a 12-volt deep cycle battery (taken from a power scooter) to the radio.? My wife had two of these batteries for her power chair, but it has since stopped working.? I use them directly to power my yaesu 857, and it works just fine, but since that radio doesn't transmit, I'd like to try using them on the zbitx.? Would I need a voltage regulator to reduce power to 6-9 volts, or can it handle the 12 volts directly?
>
> The manual says we need 6-9 volts, with at least 3A for the radio, but I'm hoping there's some wiggle room in there, because I'm hard pressed to find such an adapter already lying around here.? I'll have to go find one on amazon or something, but until then, can I use either of the above mentioned supplies w/o fear of burning up the radio?
>
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Yep, sure did, it arrived yesterday.
Can't do the initial setup w/o sighted assistance though, so have
to wait until I can get some help with that, but after that's
done, I can certainly either use it at the terminal command line,
or use the web interface to operate the radio.? Likely the web
interface would be easiest until I can work out how to get it
talking on it's own.? Likely I'll need to remove it from the case,
and swap out the pico for another pi that can handle the speech
generation, then I won't need to use the web interface anymore.?
It would be really nice being able to use the radio directly from
the unit without having to hook up/connect to additional pieces.
On 5/9/2025 11:35 PM, Buddy Brannan
wrote:
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Show quoted text
Ooh,
did you order one of these?!?
--
Buddy Brannan, KB5ELV, WRVB670?-?Erie, PA
Email: buddy@...
Mobile: (814) 431-0962
Sorry to change the subject (slightly), but I'd like to
know how far outside the specs in the manual we can go
with power adapters.? The zbitx manual says 6-9 volts is
preferred.? Will a 5V or a 10V supply break the radio? I
have both of these, and was wondering which one (if
either) I could use on the radio.? Failing that, what kind
of setup would I need to attach a 12-volt deep cycle
battery (taken from a power scooter) to the radio.? My
wife had two of these batteries for her power chair, but
it has since stopped working.? I use them directly to
power my yaesu 857, and it works just fine, but since that
radio doesn't transmit, I'd like to try using them on the
zbitx.? Would I need a voltage regulator to reduce power
to 6-9 volts, or can it handle the 12 volts directly?
The manual says we need 6-9 volts, with at least 3A for
the radio, but I'm hoping there's some wiggle room in
there, because I'm hard pressed to find such an adapter
already lying around here.? I'll have to go find one on
amazon or something, but until then, can I use either of
the above mentioned supplies w/o fear of burning up the
radio?
|
Hi,
Indeed. I wonder if you can set up the wifi network from a wpa_supplicant in the boot partition? In any case, definitely keep me posted on it. Pretty exciting!?
--
Buddy Brannan, KB5ELV, WRVB670?-?Erie, PA
Email: buddy@...
Mobile: (814) 431-0962
toggle quoted message
Show quoted text
On May 10, 2025, at 3:04?PM, Travis Siegel <tsiegel@...> wrote:
Yep, sure did, it arrived yesterday. Can't do the initial setup w/o sighted assistance though, so have
to wait until I can get some help with that, but after that's
done, I can certainly either use it at the terminal command line,
or use the web interface to operate the radio.? Likely the web
interface would be easiest until I can work out how to get it
talking on it's own.? Likely I'll need to remove it from the case,
and swap out the pico for another pi that can handle the speech
generation, then I won't need to use the web interface anymore.?
It would be really nice being able to use the radio directly from
the unit without having to hook up/connect to additional pieces.
On 5/9/2025 11:35 PM, Buddy Brannan
wrote:
Ooh,
did you order one of these?!?
--
Buddy Brannan, KB5ELV, WRVB670?-?Erie, PA
Email: buddy@...
Mobile: (814) 431-0962
Sorry to change the subject (slightly), but I'd like to
know how far outside the specs in the manual we can go
with power adapters.? The zbitx manual says 6-9 volts is
preferred.? Will a 5V or a 10V supply break the radio? I
have both of these, and was wondering which one (if
either) I could use on the radio.? Failing that, what kind
of setup would I need to attach a 12-volt deep cycle
battery (taken from a power scooter) to the radio.? My
wife had two of these batteries for her power chair, but
it has since stopped working.? I use them directly to
power my yaesu 857, and it works just fine, but since that
radio doesn't transmit, I'd like to try using them on the
zbitx.? Would I need a voltage regulator to reduce power
to 6-9 volts, or can it handle the 12 volts directly?
The manual says we need 6-9 volts, with at least 3A for
the radio, but I'm hoping there's some wiggle room in
there, because I'm hard pressed to find such an adapter
already lying around here.? I'll have to go find one on
amazon or something, but until then, can I use either of
the above mentioned supplies w/o fear of burning up the
radio?
|
