Topics

5w on 40 meters

Maurice Bersan
 

So I decided to check the output of my stock v5. These are the results CW.
80m  18w
40m    5w
30m    14w
20m     10w
15m     7w
10m      4w
Used two different power meters and two different dipole antennas and two different tuners. I don't have a lot of test gear so any clues as to where I should start looking?
Thanks in advance

Curt
 

Maurice

funny thing, my own v4 has a similar response of low power on 40m CW.  interesting you are getting it on a v5.  I am getting around 5w or so using a WM2 wattmeter on 40m, maybe just around 10w or so on 80m, and a boost in power as you see on 30 and 20 meters. 

I think the v5 retains the toroids feeding the 45 MHz xtal filter as in the v4?  now what might these have to do with CW transmit?  well I suspect some strange leakage involving these coils and other parts, as the ubitx seeks to 'leak' CW from the PLL direct through the mixer - without mixing as the diodes are biased.  as I tried to install a second xtal filter, the 40m leakage matter had more impact and my 40m output dipped a couple watts only.  

I am thinking you should enjoy what your nice rig does.  If you have an audio oscillator, you might find that you have better SSB output on 40m?  I don't see it is worth a lot of work to get from say 5 to 10 watts CW on 40m - its a tiny fraction of an S-unit. 

some have replaced those 45 MHz toroids with little (but high enough Q) shielded inductors, curing some spurs that mar the v4 on SSB and as part of the harmonic cure.  I have some, but not yet installed (I am enjoying a clean signal on lower bands already).

I tend to see a nice enough v5 you have.  it would be good to hear if any other v5's are doing this - but I don't see a huge reason to fix what you have. 

Curt wb8yyy

Mike Kilpatrick
 

My v5 is following the same pattern of output power vs band and I’m not terribly worried about it.  As Curt said the difference between 5 and 10 watts results in only a fraction of an S-point on receive.

 

Mike VK2DJP

 

M & J Kilpatrick
8 Chablis Drive
Cessnock
NSW 2325

Phone: +61 411 153 548

 

From: Curt via Groups.Io
Sent: Thursday, October 17, 2019 12:31
To: BITX20@groups.io
Subject: Re: [BITX20] 5w on 40 meters

 

Maurice

funny thing, my own v4 has a similar response of low power on 40m CW.  interesting you are getting it on a v5.  I am getting around 5w or so using a WM2 wattmeter on 40m, maybe just around 10w or so on 80m, and a boost in power as you see on 30 and 20 meters. 

I think the v5 retains the toroids feeding the 45 MHz xtal filter as in the v4?  now what might these have to do with CW transmit?  well I suspect some strange leakage involving these coils and other parts, as the ubitx seeks to 'leak' CW from the PLL direct through the mixer - without mixing as the diodes are biased.  as I tried to install a second xtal filter, the 40m leakage matter had more impact and my 40m output dipped a couple watts only.  

I am thinking you should enjoy what your nice rig does.  If you have an audio oscillator, you might find that you have better SSB output on 40m?  I don't see it is worth a lot of work to get from say 5 to 10 watts CW on 40m - its a tiny fraction of an S-unit. 

some have replaced those 45 MHz toroids with little (but high enough Q) shielded inductors, curing some spurs that mar the v4 on SSB and as part of the harmonic cure.  I have some, but not yet installed (I am enjoying a clean signal on lower bands already).

I tend to see a nice enough v5 you have.  it would be good to hear if any other v5's are doing this - but I don't see a huge reason to fix what you have. 

Curt wb8yyy

 

Dave Dixon
 

Here are my results on my V5.
80...14 watts.
40..  10 watts.
30    9 watts.
20    10 watts.
17 to 10 mtrs 5 watts.
the only mod is fit the cw keying resistors and a 5 inch TFT screen.
worked indonisia on 9th october 2019 with 579 on 40 mtrs;
verified via eqsl.

I also have a V3 with 2 line blue lcd this delivers
17 watts on 80.
14 watts on 40
11 watts on 30.
12 watts on 20
 9 watts on 17.
 7 watts on 15.
 5 watts on 10..
again no mods only the cw resistors.
Im very impressed with both radios.

all my radios are home made from kits..
i dont own any commercial radios at all save for a 2 mtr fm transceiver
thats the only microphone in the shack..
Aerial is an off centre fed dipole at 25 feet.

Dave G0AYD.QTHR QRZ.COM.

 

On Wed, 16 Oct 2019 at 23:46, Maurice Bersan via Groups.Io <Vk6hly=yahoo.com@groups.io> wrote:
So I decided to check the output of my stock v5. These are the results CW.
80m  18w
40m    5w
30m    14w
20m     10w
15m     7w
10m      4w
Used two different power meters and two different dipole antennas and two different tuners. I don't have a lot of test gear so any clues as to where I should start looking?
Thanks in advance

Curt
 

Dave

all very cool!  your ubitx pair seems have not gotten the 40m malady (its not that huge) that affects maybe just a small number of our rigs.  has me wondering what the producibility difference might be.  the only sources of stray part leakage that folk have cited are the 45 MHz inductors and the stock relays (either inside or outside the part as its mounted). 

honestly this matter had no impact to me until I started mods to remedy v4 SSB spurs. 

I have done a decent amount of CW on the ubitx - I was addicted to it for months.  crazy when I have rigs with much better QSK but I got used to its behavior.  I did work a little DX with it on 40m SSB using my vertical.   

John

if you are interested, monitor your 40m CW power while you touch those 45 MHz inductors.  I can tune mine up to around 10 watts based upon how I touch the inductor!  all pointing to taking my v4 to the bench some day to try some shielded inductors.  I will check signal strength in receiving a nearby 10m beacon before and after.  don't know how soon I will get to this surgery. 

Curt

MVS Sarma
 

Dave,
Wherher any post power amp  lpf mod was done? Results appear fine. 

Rgards
Sarma vu3zmv


On Thu, 17 Oct 2019, 3:52 pm Dave Dixon, <wylyeguy2@...> wrote:
Here are my results on my V5.
80...14 watts.
40..  10 watts.
30    9 watts.
20    10 watts.
17 to 10 mtrs 5 watts.
the only mod is fit the cw keying resistors and a 5 inch TFT screen.
worked indonisia on 9th october 2019 with 579 on 40 mtrs;
verified via eqsl.

I also have a V3 with 2 line blue lcd this delivers
17 watts on 80.
14 watts on 40
11 watts on 30.
12 watts on 20
 9 watts on 17.
 7 watts on 15.
 5 watts on 10..
again no mods only the cw resistors.
Im very impressed with both radios.

all my radios are home made from kits..
i dont own any commercial radios at all save for a 2 mtr fm transceiver
thats the only microphone in the shack..
Aerial is an off centre fed dipole at 25 feet.

Dave G0AYD.QTHR QRZ.COM.

 

On Wed, 16 Oct 2019 at 23:46, Maurice Bersan via Groups.Io <Vk6hly=yahoo.com@groups.io> wrote:
So I decided to check the output of my stock v5. These are the results CW.
80m  18w
40m    5w
30m    14w
20m     10w
15m     7w
10m      4w
Used two different power meters and two different dipole antennas and two different tuners. I don't have a lot of test gear so any clues as to where I should start looking?
Thanks in advance

Dave Dixon
 

Hello John,
                    Thanks for your reply,i own a home made radio which has full qsk and a dream to use it was produced by 2 uk amatuers in 1983 and is called the OMEGA,theres a picture of it on my qrz page,it runs 10 watts and has awsome cw filters,it weighs in at 10 kilos,all the pcb boards are housed in diecast boxes interconnecting with each other via feed through capactors and rg 174 coax,the low pass filters are enclosed in a brass sheild box and the pa is also sheilded,the radio has a brilliant receiver and was my main station until the arrival of the bitx Version 3 and now my new one the Version 5 I dont own any beams and only use a off centre fed dipole as i live in an area of conservation,i dont run any other modes than cw and have been 100% cw since 1990,you can read all about my exploits on my qrz page,I dont hunt dx and take what comes out of the speaker,i read the mail on this site with interest but have no qualms to change anything at all on any of my radios.Im waiting to hear of any news when the QSX gets released on the for sale market. have a 40 mtr qcx im impressed with.Regards Dave G0AYD..


On Thu, 17 Oct 2019 at 13:27, Curt via Groups.Io <wb8yyy=yahoo.com@groups.io> wrote:
Dave

all very cool!  your ubitx pair seems have not gotten the 40m malady (its not that huge) that affects maybe just a small number of our rigs.  has me wondering what the producibility difference might be.  the only sources of stray part leakage that folk have cited are the 45 MHz inductors and the stock relays (either inside or outside the part as its mounted). 

honestly this matter had no impact to me until I started mods to remedy v4 SSB spurs. 

I have done a decent amount of CW on the ubitx - I was addicted to it for months.  crazy when I have rigs with much better QSK but I got used to its behavior.  I did work a little DX with it on 40m SSB using my vertical.   

John

if you are interested, monitor your 40m CW power while you touch those 45 MHz inductors.  I can tune mine up to around 10 watts based upon how I touch the inductor!  all pointing to taking my v4 to the bench some day to try some shielded inductors.  I will check signal strength in receiving a nearby 10m beacon before and after.  don't know how soon I will get to this surgery. 

Curt

Dave Dixon
 

Hello Sama,
                   I have done only adding the resistors on the cw line no other mods have been done ON .Dave G0AYD.


On Thu, 17 Oct 2019 at 13:27, MVS Sarma <mvssarma@...> wrote:
Dave,
Wherher any post power amp  lpf mod was done? Results appear fine. 

Rgards
Sarma vu3zmv


On Thu, 17 Oct 2019, 3:52 pm Dave Dixon, <wylyeguy2@...> wrote:
Here are my results on my V5.
80...14 watts.
40..  10 watts.
30    9 watts.
20    10 watts.
17 to 10 mtrs 5 watts.
the only mod is fit the cw keying resistors and a 5 inch TFT screen.
worked indonisia on 9th october 2019 with 579 on 40 mtrs;
verified via eqsl.

I also have a V3 with 2 line blue lcd this delivers
17 watts on 80.
14 watts on 40
11 watts on 30.
12 watts on 20
 9 watts on 17.
 7 watts on 15.
 5 watts on 10..
again no mods only the cw resistors.
Im very impressed with both radios.

all my radios are home made from kits..
i dont own any commercial radios at all save for a 2 mtr fm transceiver
thats the only microphone in the shack..
Aerial is an off centre fed dipole at 25 feet.

Dave G0AYD.QTHR QRZ.COM.

 

On Wed, 16 Oct 2019 at 23:46, Maurice Bersan via Groups.Io <Vk6hly=yahoo.com@groups.io> wrote:
So I decided to check the output of my stock v5. These are the results CW.
80m  18w
40m    5w
30m    14w
20m     10w
15m     7w
10m      4w
Used two different power meters and two different dipole antennas and two different tuners. I don't have a lot of test gear so any clues as to where I should start looking?
Thanks in advance

MVS Sarma
 

Thanjs Dave. I use v5 and Recollect some old comments about the 40m LPF inductor actial values vs sch indicated values. 


On Thu, 17 Oct 2019, 9:06 pm Dave Dixon, <wylyeguy2@...> wrote:
Hello Sama,
                   I have done only adding the resistors on the cw line no other mods have been done ON .Dave G0AYD.

On Thu, 17 Oct 2019 at 13:27, MVS Sarma <mvssarma@...> wrote:
Dave,
Wherher any post power amp  lpf mod was done? Results appear fine. 

Rgards
Sarma vu3zmv


On Thu, 17 Oct 2019, 3:52 pm Dave Dixon, <wylyeguy2@...> wrote:
Here are my results on my V5.
80...14 watts.
40..  10 watts.
30    9 watts.
20    10 watts.
17 to 10 mtrs 5 watts.
the only mod is fit the cw keying resistors and a 5 inch TFT screen.
worked indonisia on 9th october 2019 with 579 on 40 mtrs;
verified via eqsl.

I also have a V3 with 2 line blue lcd this delivers
17 watts on 80.
14 watts on 40
11 watts on 30.
12 watts on 20
 9 watts on 17.
 7 watts on 15.
 5 watts on 10..
again no mods only the cw resistors.
Im very impressed with both radios.

all my radios are home made from kits..
i dont own any commercial radios at all save for a 2 mtr fm transceiver
thats the only microphone in the shack..
Aerial is an off centre fed dipole at 25 feet.

Dave G0AYD.QTHR QRZ.COM.

 

On Wed, 16 Oct 2019 at 23:46, Maurice Bersan via Groups.Io <Vk6hly=yahoo.com@groups.io> wrote:
So I decided to check the output of my stock v5. These are the results CW.
80m  18w
40m    5w
30m    14w
20m     10w
15m     7w
10m      4w
Used two different power meters and two different dipole antennas and two different tuners. I don't have a lot of test gear so any clues as to where I should start looking?
Thanks in advance

ajparent1/KB1GMX
 

I've seen a few that had the wrong parts (inductors were obvious) installed for
the 40M filter.

Allison

MVS Sarma
 

Thanks Allison. I measured  40m band LPF inductors were almost measuring 0.9nH  and I haddepended on the accuracy of sch and reduced turns.

regards  vu3zmv


On Thu, Oct 17, 2019 at 10:50 PM ajparent1/KB1GMX <kb1gmx@...> wrote:
I've seen a few that had the wrong parts (inductors were obvious) installed for
the 40M filter.

Allison