Azimute pointer on a G-5600 gives a wrond value
Hello thanks for reading,
I recently acquired a Yaesu G-5600 and experience the following:
When I turn the azimuth antenna, then the pointer gives an other value than when I don't turn the antenna.
It lookes that the load on the powersupply causes the pointer to indicate a different value then when there is no load.
Is this a known problem? And is there a way to solve this problem?
Thanks in advance,
PE0SAT - Jan
----- Original Message ----- From: "PE0SAT" pe0sat@vgnet.nl To: amsat-bb@amsat.org Sent: Tuesday, August 25, 2009 6:42 PM Subject: [amsat-bb] Azimute pointer on a G-5600 gives a wrond value
Hello thanks for reading,
I recently acquired a Yaesu G-5600 and experience the following:
When I turn the azimuth antenna, then the pointer gives an other value than when I don't turn the antenna.
It lookes that the load on the powersupply causes the pointer to indicate a different value then when there is no load.
Is this a known problem? And is there a way to solve this problem?
Thanks in advance,
PE0SAT - Jan
Hi Jan, PE0SAT
Connect a voltmeter between terminals A1 and A3 of the control box The voltage across the 500 ohm potentiometer into the azimuth rotator must remain constant at about 6 volt while turning the azimuth. A1 and A3 are connected via a 15 ohm resistor to the output of a voltage regulator Q2 UA7806C in the schematic diagram. The same regulator power supply the elevation potentiometer via a 15 ohm resistor so that connecting the voltmeter across E1 and E3 and rotating the elevation the voltage must remain constant as well. If the voltage between A1 and A3 changes and if between E1 and E3 do not change it is not a problem of the voltage regulator but probably someting is overloading the control box power supply while rotating the azimuth. In this case the drop of voltage must appear as well at the input of the regulator and you can check it measuring the voltage at pin 7 of the 8 pin external control connector because pin 7 is directly connected to the regulator input.
Have fun
73" de
i8CVS Domenico
On Tue, August 25, 2009 19:45, i8cvs wrote:
When I turn the azimuth antenna, then the pointer gives an other value than when I don't turn the antenna.
Hi Jan, PE0SAT
Hi Domenico,
As allways you give great answers :))
Connect a voltmeter between terminals A1 and A3 of the control box The voltage across the 500 ohm potentiometer into the azimuth rotator must remain constant at about 6 volt while turning the azimuth.
There is 9.2 volt DC :( looks that the 7806 is defect. But one thing that puzzles me, i don't see a connection from the negative site of the ac-dc diode bridge to ground.
i8CVS Domenico
73's Jan
----- Original Message ----- From: "PE0SAT" pe0sat@vgnet.nl To: "i8cvs" domenico.i8cvs@tin.it Cc: "AMSAT-BB" amsat-bb@amsat.org Sent: Tuesday, August 25, 2009 9:38 PM Subject: Re: [amsat-bb] Azimute pointer on a G-5600 gives a wrong value
On Tue, August 25, 2009 19:45, i8cvs wrote:
Connect a voltmeter between terminals A1 and A3 of the control box The voltage across the 500 ohm potentiometer into the azimuth rotator must remain constant at about 6 volt while turning the azimuth.
73" de i8CVS Domenico
Hi Domenico,
As allways you give great answers :))
There is 9.2 volt DC :( looks that the 7806 is defect. But one thing that puzzles me, i don't see a connection from the negative site of the ac-dc diode bridge to ground.
73's Jan
Hi Jan, PE0SAT
OK the 7806 is defective and must be changed but since you have to open the controller of G-5600 I suggest you to improve the regulator performance because the original capacitor C9 0.01 uF at the regulator output is a very small bypass capacitor.
Solder a ceramic capacitor of 0.1 uF in parallel to an electrolitic capacitor ranging from 1 to 10 uF and solder it both at the input and as well at the output of the regulator as this cure will prevent possible autoscillations of the regulator itself in a wide frequency band.
The negative path of the bridge to ground for the regulator Q2 is through series diodes D5-D4-D3 and ground so that a drop of about 0.6 x 3 = 1.8 volt is developed and this is made to get a minimum voltage of 1.8 volt and not 0 volt when the wiper of the 500 ohm potentiometer is fully grounded.
The negative path of the bridge to ground for B1 C1 and B2 C2 to supply the +/- voltages to the operational amplifiers is through the series transistor Q1 and zener diode D2
The negative path of the bridge for the coils of relay RY1-RY2-RY3 and RY4 is directly connected floating to the bridge and insulated from the ground.
Have fun and 73" de
i8CVS Domenico
On Wed, August 26, 2009 03:10, i8cvs wrote:
Hi Jan, PE0SAT
Hi Domenico,
OK the 7806 is defective and must be changed but since you have to open the controller of G-5600 I suggest you to improve the regulator performance because the original capacitor C9 0.01 uF at the regulator output is a very small bypass capacitor.
I have replaced the 7806 and made the modifications you metioned and now every think is working like a charme :))
Solder a ceramic capacitor of 0.1 uF in parallel to an electrolitic capacitor ranging from 1 to 10 uF and solder it both at the input and as well at the output of the regulator as this cure will prevent possible autoscillations of the regulator itself in a wide frequency band.
Have fun and 73" de
i8CVS Domenico
Grazie per l'aiuto / Thank you for helping
73's PE0SAT
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PE0SAT