Stefan

No 100 hz visible on the NL 9222 GRABBER.

mal/g3kev

 

----- Original Message -----

From: Stefan Schäfer

To: [email protected]

Sent: Tuesday, August 09, 2011 7:08 PM

Subject: Re: LF: 137 ck

Mal, Gary,

Right now i can see the 100 Hz sidebands on Gary's grabber! O copy ;-)

Am 09.08.2011 17:57, schrieb mal hamilton:

Graham

The display looks clean this end also the audio sounds pure with no 100 hz hum as monitored on an independent RX

I have the proper C's es L for decouping as per Decca instructions with this TX.

What instructions? What L? A L at 50 Hz? A L has a R and just causes losses. What you need is C! Just add some 10000 uF to the PSU.

73, Stefan

With a strong signal on some Grabbers there will be the dog bone effect with leading/trailing edge blips from keying carrier on/off

but on scope no transients visible.

73 de mal/g3kev

 

----- Original Message -----

From: Graham

To: [email protected]

Sent: Monday, August 08, 2011 11:49 PM

Subject: Re: LF: 137 ck

That's  the problem  with  modern   digital  technology , the  dynamic range  exceeds , that  of the  MK-1   eye  ball , 30 db is  1000:1  , will  show at  20 db over the  noise and  would  not  show on the  scope

 

Use a  reasonable   decoupling   capacitor  , and look at the  psu   voltage  using  a  (cheap) sound  card  (with high z resistive ladder for  safety) ..use  Wolf's   SPEC-LAB   to   view  the dB  attenuation  at  50, 100, 150 , 200  Hz  etc

 

Depending  on the  loop  bandwidth  of the  stabiliser , keying  may  also  induce  transits  , use the  peak  hold to  observe the  generated  spectrum

 

G..

From: mal hamilton

Sent: Monday, August 08, 2011 8:29 PM

To: [email protected]

Subject: Re: LF: 137 ck

No hum Gary

I am monitoring on the scope and sig is vy clean

mal/g3kev

 

----- Original Message -----

From: Gary - G4WGT

To: [email protected]

Sent: Monday, August 08, 2011 8:19 PM

Subject: Re: LF: 137 ck

OK Mal,

Captures are at 10 minute intervals, but I have saved you going to SpecSavers as I have enlarged the frequency readout.

BTW...do you have some 100Hz hum on your transmission, look at my grabber to check.

73

Gary - G4WGT.

On 8 August 2011 19:28, mal hamilton <[email protected]> wrote:

Yes Gary

Your grabber seems to have a long delay before display es the times and freq hard to read

otherwise sensitivity seems ok at present for distance

73 de mal/g3kev

 

----- Original Message -----

From: Gary - G4WGT

To: [email protected]

Sent: Monday, August 08, 2011 7:21 PM

Subject: Re: LF: 137 ck

Mal,

You wrote.........While testing earlier find NO UK GRABBERS working

My 500kHz & 137kHz grabber runs 24/7....

http://myweb.tiscali.co.uk/wgtaylor/grabber2.html

Gary - G4WGT.

On 8 August 2011 18:33, mal hamilton <[email protected]> wrote:

Just finished my new PSU 60V/10A psu. While testing earlier find NO UK GRABBERS working and DK7FC has a SPURIOUS wobble signal right on 137.7

I will be QRV for a while from now on 137.7 qrs3 for DX qso's and will work locals on CW

73 De Mal/G3KEV