Hello - I have a mast-mounted UHF antenna amp which uses a DC power injector. The original power adapter unit broke, and the company does not make it It was 18V .3A rating.

Not having an 18V supply, I hooked up a 9V 1A Power adapter, connected the leads to the coax injector feed - it works better than before ! no dropouts, erratic noise etc...very quiet, clear signal.

I was able to finally track down an 18V adapter, and it has been ordered..but my question is - is there any possibility that the lower voltage will damage the circuit ? I know some circuits are designed to operate within a range of voltages..I am pretty sure higher than rated voltage is a no-no, just not sure about using 50% less than the original supply ...I figured it would either work, or it wouldn't .I remember the original 18V wall wart ran pretty hot...

Bill Clark

 

If it works properly at 9V than it's quite unlikely that it will be damaged by long term operation at that voltage.
Since it appears to work better at 9V, you may find that you won't want to run it a 18V when the new adapter arrives.

 

Thank you for the kind reply -- I will embrace the miracle ... one question - what would be the best way to permanently connect the wire from the 9V adapter to the coaxial cable ? Right now, I ahve simply wrapped the wires ... was thinking that a simple barrier strip would do the trick ... I can post a picture if u like...

 

what would be the best way to permanently connect the wire from the 9V adapter to the coaxial cable ? Right now, I ahve simply wrapped the wires ... was thinking that a simple barrier strip would do the trick

How was the original supply connected?
You can solder the wires or use a barrier strip, it's not critical.

 

Here is the original setup (Winegard)
Right now, I have the wires from 9V PS twisted together with the stripped end of a piece of RG-6, and then onto the splitter ..Originally the voltage was applied through the F connector along the length of Coax. I think I have a barrier strip around ...solder for sure ..

 

here is my "cob-job" which works perfectly

----------------------

 

If you want to get fancy, you could solder the 9V wires to an F-female connector (cannibalize it from the broken supply) and then use the coax cable to make the connection to the splitter.

 

I cannot find the original supply for f-connector ..

I was thinking I could use this:

Currently, This is all I have in the way of female F connectors - I think I will break out the soldering iron today

 

The top one is good. It just needs a solder tab for the ground connection.

The bottom one is just a female-female feedthrough and won't really work.

 

I had an idea when looking through a box of antenna "stuff"


So I figured this wall plate would at least secure the coax connection, so now I needed a center conductor, which I harvested from some RG-6


NO plate to solder to for ground, so I tucked the braid under the threaded F-Connector sleeve with no solder, and very sloppily soldered the center connection .black tape helps as stress relief ...Opera never sounded better -- will get a surface-mount matching Ivory receptacle box to attach the wall plate to, and call this a 9 Volt wrap. How's that for Yankee Ingenuity Thank you cor the comments..

 

Looks like a winner for YI.

 

Only rare elements which may be fast damaged at PS near the one-nil jump point are old soviet 176 series CMOS logics. Most of all other circuitry have no this illness except the power MOSFETs in SMPS what demand no less as saturation voltage on gates to not cook a devices.