23cm DATV RF PA module M68719
Posted: Sat Mar 22, 2014 7:21 pm
Hi All,
Just been given an amplifier with one of these units inside and plan to use it with DVB-S RF, so it is requiring it to be used as a linear.
Can only find a single page data sheet on the web, so have no idea how the unit needs to be biased.
GB3TM uses one of these modules (http://www.arfon.info/GB3TMDigital.htm - see fig 6) so my quest appears to be reasonable.
Current amplifier is designed for FM and has pin 1 as RF in, pin 2 as 13V, pin 3 as 8v, pin 4 as 13v, and pin 5 as RF out.
Quiecent current appears to be 640mA at 13V with input and output terminated in 50R.
Amplifier appears to be unstable, but ground straps were not included from module substrate to PCB ground plane. Also, there a couple of high value electrolytics on the 13V rail that could have easily dried up.
So before the unit is disassembled and fixed, a full datasheet would be most appreciated. Or some indication if the supplies above are OK for linear operation. I appreciate that the unit will probably only generate a couple of watts for this mode.
Any help appreciated.
-Mark
Just been given an amplifier with one of these units inside and plan to use it with DVB-S RF, so it is requiring it to be used as a linear.
Can only find a single page data sheet on the web, so have no idea how the unit needs to be biased.
GB3TM uses one of these modules (http://www.arfon.info/GB3TMDigital.htm - see fig 6) so my quest appears to be reasonable.
Current amplifier is designed for FM and has pin 1 as RF in, pin 2 as 13V, pin 3 as 8v, pin 4 as 13v, and pin 5 as RF out.
Quiecent current appears to be 640mA at 13V with input and output terminated in 50R.
Amplifier appears to be unstable, but ground straps were not included from module substrate to PCB ground plane. Also, there a couple of high value electrolytics on the 13V rail that could have easily dried up.
So before the unit is disassembled and fixed, a full datasheet would be most appreciated. Or some indication if the supplies above are OK for linear operation. I appreciate that the unit will probably only generate a couple of watts for this mode.
Any help appreciated.
-Mark