¿ªÔÆÌåÓý

  1. BITX20
  2. Topics

Output power on Ubitx v3

 

So I build a Ubitx v3.

On 80m i get 9w output power

On 40m i get 4w output power.

?

What can cause this? Isnt it supposed to output near 10w range on 40m?

?

73'de LB6CI
 

Jan

my v4 performs very similar.? abt 10w on 80m, 4 to 5w on 40m, 7w on 30 and 20m, then diminishing down to 4w on 10m.?

there appears to be a mystery resonance that reduces power on 40m.? it is even more noticed when trying to add filtering on the 45 MHz IF.? there is a ca capacitor, C22 maybe - remove it and 40m power drops even further.?

not a huge difference between 4 and 7 watts.? it isn't worth too much struggle to remedy it (if it can even be done).? why do other builders report different higher power on 40m?? it might be the mystery of their circuit, or their power meter.?

I sense all it well with your rig in terms of output power - do enjoy it !

73 Curt WB8YYY
Joe Puma
 

¿ªÔÆÌåÓý

Do Allison power flattening. I have mine outputting 12w on 80, 14w on 40, 15w on 20 and as low as 6w on 10meter.?

Joe
Kd2nfc?



On May 3, 2019, at 8:47 PM, Curt via Groups.Io <wb8yyy@...> wrote:

Jan

my v4 performs very similar.? abt 10w on 80m, 4 to 5w on 40m, 7w on 30 and 20m, then diminishing down to 4w on 10m.?

there appears to be a mystery resonance that reduces power on 40m.? it is even more noticed when trying to add filtering on the 45 MHz IF.? there is a ca capacitor, C22 maybe - remove it and 40m power drops even further.?

not a huge difference between 4 and 7 watts.? it isn't worth too much struggle to remedy it (if it can even be done).? why do other builders report different higher power on 40m?? it might be the mystery of their circuit, or their power meter.?

I sense all it well with your rig in terms of output power - do enjoy it !

73 Curt WB8YYY

 

Anymore info on this would be great, perhaps a link or something? :)?

Thanks =)
 

Ok, thanks :)
Joe Puma
 

¿ªÔÆÌåÓý

Look in this groups wiki

On May 3, 2019, at 9:56 PM, Jan Ivar Haugen via Groups.Io <haugen84@...> wrote:

Anymore info on this would be great, perhaps a link or something? :)?

Thanks =)
 

Curt,

C22 must ALWAYS be in circuit. If you remove it there will be no output. If you skip it and
put a filter then DC from Q22 will unbalance the mixer..

Raj

At 04/05/2019, you wrote:

Jan

my v4 performs very similar.? abt 10w on 80m, 4 to 5w on 40m, 7w on 30 and 20m, then diminishing down to 4w on 10m.?

there appears to be a mystery resonance that reduces power on 40m.? it is even more noticed when trying to add filtering on the 45 MHz IF.? there is a ca capacitor, C22 maybe - remove it and 40m power drops even further.?

not a huge difference between 4 and 7 watts.? it isn't worth too much struggle to remedy it (if it can even be done).? why do other builders report different higher power on 40m?? it might be the mystery of their circuit, or their power meter.?

I sense all it well with your rig in terms of output power - do enjoy it !
 

Was it in CW keydown or SSB?


Il 04/mag/2019 02:39, "Jan Ivar Haugen via Groups.Io" <haugen84=[email protected]> ha scritto:

So I build a Ubitx v3.

On 80m i get 9w output power

On 40m i get 4w output power.

?

What can cause this? Isnt it supposed to output near 10w range on 40m?

?

73'de LB6CI
 

Raj

sure - you interpreted me too literally!? I have tried placing a xtal filter there, with various forms of matching, and an LC filter - to improve spurious in the SSB path.? its the CW path on 40m (and 80m) that is corrupted by these modifications.? and removing C22 impacts CW on these lower bands - in at least 2 v4's (N3SB is the other).?

How is it related to this question on why Jan's 40m output is down a bit?? maybe I was presumptuous that he was measuring output power on CW?? possibly he was - as for most of our rigs we tend to measure output on CW.? however of course the ubitx is different in this regard.?

all okay.? for now I am content with my ubitx doing well on all bands CW, and the lower bands up to 17m on SSB (with low enough spurious).?

Curt
 

Hi to EVERYBODY in this group.
Anybody can help to homebrew good? HF QRP ANTENNA TUNER ?? My email bsnvu2yc73s@....? De VU2UYC. Balsun from Kerala, INDIA.

On Sat, May 4, 2019 at 5:10 PM Curt via Groups.Io <wb8yyy=[email protected]> wrote:
Raj

sure - you interpreted me too literally!? I have tried placing a xtal filter there, with various forms of matching, and an LC filter - to improve spurious in the SSB path.? its the CW path on 40m (and 80m) that is corrupted by these modifications.? and removing C22 impacts CW on these lower bands - in at least 2 v4's (N3SB is the other).?

How is it related to this question on why Jan's 40m output is down a bit?? maybe I was presumptuous that he was measuring output power on CW?? possibly he was - as for most of our rigs we tend to measure output on CW.? however of course the ubitx is different in this regard.?

all okay.? for now I am content with my ubitx doing well on all bands CW, and the lower bands up to 17m on SSB (with low enough spurious).?

Curt

1 - 10 of 10