power vs frequency

General discussion and support for the Peaberry SDR V2.

power vs frequency

Postby kb3cuf » Thu Jan 29, 2015 4:38 pm

Hi- I am perplexed by this- 60/40/30/20 rig V2 about 2 yrs old that I am revisiting. I generally used it as an RX until a strike last summer- so I am reconstructing from a broken unit.
HDSDR CW into a dummy load-
at 7.1 Mhz I get about 1/2 watt.
at 6.1 about 3/4 watt
At 5.1 a full watt

Same behavior on 20M- below the band it has more power

It seems that the transformer passbands are too low- but I know its not the output filters- since it happens on 30/20
To be sure, I rewound all the transformers last night. (!)
Is it possible that there is some problem with HDSDR that is shifting transmit freq? in the setup? W8.1/newest HDSDR/Cfgsdr, ext-IO.dll, etc.
I have not used a freq. counter as yet to determine carrier freq.
Also, in Cfgsdr what rig do I pick? Softrock 6.3? Ensemble? etc.

The rig seems to be hearing OK

73
Larry
kb3cuf
 
Posts: 44
Joined: Thu Feb 06, 2014 1:51 pm

Re: power vs frequency

Postby W4MMP » Thu Jan 29, 2015 5:11 pm

kb3cuf wrote:Hi- I am perplexed by this- 60/40/30/20 rig V2 about 2 yrs old that I am revisiting. I generally used it as an RX until a strike last summer- so I am reconstructing from a broken unit.
HDSDR CW into a dummy load-
at 7.1 Mhz I get about 1/2 watt.
at 6.1 about 3/4 watt
At 5.1 a full watt

Same behavior on 20M- below the band it has more power

It seems that the transformer passbands are too low- but I know its not the output filters- since it happens on 30/20
To be sure, I rewound all the transformers last night. (!)
Is it possible that there is some problem with HDSDR that is shifting transmit freq? in the setup? W8.1/newest HDSDR/Cfgsdr, ext-IO.dll, etc.
I have not used a freq. counter as yet to determine carrier freq.
Also, in Cfgsdr what rig do I pick? Softrock 6.3? Ensemble? etc.

The rig seems to be hearing OK

73
Larry


Hi Larry,
I highly recommend setting HDSDR to FM when performing power tests. Set the slider to maximum output power. This way the HDSDR generated volume does not come into play.
In CFGSDR, in the init tab set the rig to Ensemble RXTX.
73
Ron / W4MMP
W4MMP
 
Posts: 579
Joined: Fri Jan 03, 2014 3:31 pm
Location: Lovettsville, Virginia FM19EG

Re: power vs frequency

Postby kb3cuf » Thu Jan 29, 2015 6:14 pm

Will do. I have been using Powersdr 1.12 .something up to know. I want to try David's CW program- thats why off XP on to W8.1.

I'll let you know this evening how things work out. Also installed the 2nd pair of FETs- the heatsink is getting quite warm now.

Larry
kb3cuf
 
Posts: 44
Joined: Thu Feb 06, 2014 1:51 pm

Re: power vs frequency

Postby kb3cuf » Fri Jan 30, 2015 12:13 am

So the rig is solid 1 W in FM mode. Also found a slightly loose PL259 that may have been an issue (at 12:30 AM).

So it works. And I can get more- if I boost the output on the Peaberry input I can get 2W. I assume that is in distortion land. I built a Hardrock driver board and set it up for 1W in. I could get 10W although that probably will annoy my input attenuator. So how do I set my gain structure? HDSDR half and Peaberry gain to suit? or HDSDR full up and peaberry backed down?

XP I did not have the mixer controls I have in W8.1

Larry
kb3cuf
 
Posts: 44
Joined: Thu Feb 06, 2014 1:51 pm

Re: power vs frequency

Postby W4MMP » Fri Jan 30, 2015 12:57 am

kb3cuf wrote:So the rig is solid 1 W in FM mode. Also found a slightly loose PL259 that may have been an issue (at 12:30 AM).

So it works. And I can get more- if I boost the output on the Peaberry input I can get 2W. I assume that is in distortion land. I built a Hardrock driver board and set it up for 1W in. I could get 10W although that probably will annoy my input attenuator. So how do I set my gain structure? HDSDR half and Peaberry gain to suit? or HDSDR full up and peaberry backed down?

XP I did not have the mixer controls I have in W8.1

Larry


Larry,
Set the Peaberry sound device levels to maximum and control the power levels with HDSDR only. I keep the HDSDR power output slider at maximum and control power output with the volume control. This simulates keeping the ALC where it should be. Don't drive the Peaberry beyond 1 watt or you will be in distortion land. When using the Hardrock driver board (I have one also)you will never need any more than about 0.5W output from the Peaberry to achieve full output from the Hardrock driver board.
73
Ron / W4MMP
W4MMP
 
Posts: 579
Joined: Fri Jan 03, 2014 3:31 pm
Location: Lovettsville, Virginia FM19EG

Re: power vs frequency

Postby kb3cuf » Fri Jan 30, 2015 1:09 am

I populated the input attenuator so I could drive the amp with 1 W. If I get better linearity with 1/2 W drive I'll pull them out.
Larry
kb3cuf
 
Posts: 44
Joined: Thu Feb 06, 2014 1:51 pm

Re: power vs frequency

Postby kb3cuf » Fri Jan 30, 2015 1:12 am

So your advice is HDSR maxed and Peaberry vol to suit? or Peaberry maxed and HDSDR to suit? You suggested both :lol:
kb3cuf
 
Posts: 44
Joined: Thu Feb 06, 2014 1:51 pm

Re: power vs frequency

Postby W4MMP » Fri Jan 30, 2015 3:22 am

kb3cuf wrote:So your advice is HDSR maxed and Peaberry vol to suit? or Peaberry maxed and HDSDR to suit? You suggested both :lol:


Hi Larry,
Huh? Set the Peaberry mixer volume controls to max. The HDSDR output power to max. Control the output power with the volume control of HDSDR. Not really sure how else to say it.
73
Ron / W4MMP
W4MMP
 
Posts: 579
Joined: Fri Jan 03, 2014 3:31 pm
Location: Lovettsville, Virginia FM19EG

Re: power vs frequency

Postby W4MMP » Fri Jan 30, 2015 3:31 am

Ok, yep I see my mistake. I should have said Mic Gain (not volume control) for adjusting the output power. Old age moment ;)
73
Ron / W4MMP
W4MMP
 
Posts: 579
Joined: Fri Jan 03, 2014 3:31 pm
Location: Lovettsville, Virginia FM19EG

Re: power vs frequency

Postby kb3cuf » Fri Jan 30, 2015 5:13 pm

OK, I get it now. Since I operate CW I will set HDSDR to Max, adjust Peaberry volume to no more than 3-5 watts out of my rig+amp combo into a dummy load. I'll listen on the TenTec Rebel for tone before I go live to the antenna.

The Peaberry is nice and stable now that it is in one of those steel cases, and has a 20A 13.8V supply. Wall warts work for RX but not so great for TX.

Hopefully QRV this weekend on 40M

73
Larry
kb3cuf
 
Posts: 44
Joined: Thu Feb 06, 2014 1:51 pm


Return to Peaberry SDR V2

Who is online

Users browsing this forum: No registered users and 4 guests

cron