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U3S power out on 630M

 

For those that have used their U3S on 630M, what was your power out into a dummy load with only one BS170 and 5V to the PA?? I did see a modification that changes a capacitor value to increase the power output but I was hoping to get some data before any mods were done.

My U3S is capable of transmitting on 20, 30, 40, 80, 160, and 630 meters and works very well with no build issues other than low power on 630M.

Thanks
Tim KB2MFS
 

Hi Tim?

There is some info on 630m power on the U3S modifications page see?

73 Hans G0UPL?
?

On Jan 10, 2018 05:33, "Tim and Janet" <kb2mfs@...> wrote:
For those that have used their U3S on 630M, what was your power out into a dummy load with only one BS170 and 5V to the PA?? I did see a modification that changes a capacitor value to increase the power output but I was hoping to get some data before any mods were done.

My U3S is capable of transmitting on 20, 30, 40, 80, 160, and 630 meters and works very well with no build issues other than low power on 630M.

Thanks
Tim KB2MFS

 

¿ªÔÆÌåÓý

For what it's worth I get 260 milliwatts out of my completely "stock" U3S on 630m running 5V to a single BS170. I used the 25 turn winding for T1, not the bifilar option.

I get 240 milliwatts on 2200m where my U3S is happily transmitting WSPR at the moment.

73,
Paul N1BUG



On 01/10/2018 12:48 AM, Hans Summers wrote:
Hi Tim?

There is some info on 630m power on the U3S modifications page see?

73 Hans G0UPL?
?

On Jan 10, 2018 05:33, "Tim and Janet" <kb2mfs@...> wrote:
For those that have used their U3S on 630M, what was your power out into a dummy load with only one BS170 and 5V to the PA?? I did see a modification that changes a capacitor value to increase the power output but I was hoping to get some data before any mods were done.

My U3S is capable of transmitting on 20, 30, 40, 80, 160, and 630 meters and works very well with no build issues other than low power on 630M.

Thanks
Tim KB2MFS
_._,_._,_


-- 
Paul
N1BUG  160m-2m         DXCC Honor Roll
WI2XTC 2200m-630m Experimental license
FN55mf      ME      Piscataquis County

David Bowman
 

Hi Tim.

I changed the capacitor from 10n to 100n and I get somewhere between 250 and 300mW on 630m with a 5V supply and a single FET

In reality you will probably need an amplifier as 250mW into an inefficient antenna is probably OK for a few reports out to 50 miles
but to get much further you will probably need an external amplifier, rather than pushing the U3S to its limits.

FYI.? It's normal on 630 and 2200m to set the U3S to send your EIRP rather than transmitter output power.? That takes care of the antenna efficiency so the reports are more meaningful when compared on WSPRnet.

See you on MF


73

David
 

Thanks Hans.?? I had read that mod information but it seemed to only show the power out after the mod.? I wanted to make sure I didn't have an issue with the lpf possibly before doing the mod.

Great little radio and very impressed.? WSPR spots last night in Europe on 80 meters.? I was thinking of possibly ordering another one to dedicate to 2200m, 630m, and 160m.

Tim KB2MFS


On Jan 9, 2018 11:49 PM, "Hans Summers" <hans.summers@...> wrote:
Hi Tim?

There is some info on 630m power on the U3S modifications page see?

73 Hans G0UPL?
?

On Jan 10, 2018 05:33, "Tim and Janet" <kb2mfs@...> wrote:
For those that have used their U3S on 630M, what was your power out into a dummy load with only one BS170 and 5V to the PA?? I did see a modification that changes a capacitor value to increase the power output but I was hoping to get some data before any mods were done.

My U3S is capable of transmitting on 20, 30, 40, 80, 160, and 630 meters and works very well with no build issues other than low power on 630M.

Thanks
Tim KB2MFS

 

Thanks David.? I actually sent you an email last night regarding your 472 kHz amp kit/board.

I will most likely put up a Marconi type antenna for this band. My wife already comments about the number of antennas I have in the air.? This band is completely new to me and I have been doing quite a bit of reading lately.?

The email I sent you was to an AOL account if I remember correctly.?? Let me know if this is not a current address.

Thanks

Tim KB2MFS


On Jan 10, 2018 9:12 AM, "David Bowman via Groups.Io" <g0mrf=[email protected]> wrote:
Hi Tim.

I changed the capacitor from 10n to 100n and I get somewhere between 250 and 300mW on 630m with a 5V supply and a single FET

In reality you will probably need an amplifier as 250mW into an inefficient antenna is probably OK for a few reports out to 50 miles
but to get much further you will probably need an external amplifier, rather than pushing the U3S to its limits.

FYI.? It's normal on 630 and 2200m to set the U3S to send your EIRP rather than transmitter output power.? That takes care of the antenna efficiency so the reports are more meaningful when compared on WSPRnet.

See you on MF


73

David

 

Thanks Paul.?? That information is exactly what I was looking for.

73
Tim KB2MFS


On Jan 10, 2018 12:11 AM, "N1BUG" <paul@...> wrote:

For what it's worth I get 260 milliwatts out of my completely "stock" U3S on 630m running 5V to a single BS170. I used the 25 turn winding for T1, not the bifilar option.

I get 240 milliwatts on 2200m where my U3S is happily transmitting WSPR at the moment.

73,
Paul N1BUG



On 01/10/2018 12:48 AM, Hans Summers wrote:
Hi Tim?

There is some info on 630m power on the U3S modifications page see?

73 Hans G0UPL?
?

On Jan 10, 2018 05:33, "Tim and Janet" <kb2mfs@...> wrote:
For those that have used their U3S on 630M, what was your power out into a dummy load with only one BS170 and 5V to the PA?? I did see a modification that changes a capacitor value to increase the power output but I was hoping to get some data before any mods were done.

My U3S is capable of transmitting on 20, 30, 40, 80, 160, and 630 meters and works very well with no build issues other than low power on 630M.

Thanks
Tim KB2MFS

 

Tim/David,

My U3S puts out around 4 watts with the PA Kit measured with a DSO into a 50 ohm dummy load.? I did not know about the wsprnet convention of using EIRP.??

Thanks for sharing!

I have an 18 ft Marconi tee top loaded.

Dave, W4VU

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