brandonb959 wrote:Hello all,
The Harris 25K that I had worked on for a while and have posted about on here has been on the air since July with really no issues. Recently we began having problems with the output meter. The Forward/Reflected Switch had dirty contacts and so I replaced it with a basic toggle switch (better than sending Harris a ton of money) the schematic just showed a basic dpst switch. The meter worked intermittently even with the old switch, which you could tap on and it began working again, but now with the brand new switch the meter works sometimes, but not others? I have measured around 8vdc across the meter when the switch was set to forward power and about 400mv when it was set to reflected power, even thought the meter was not working. These measurements seem to be about right. It sounds to me like the meter is going bad, but just wanted a second opinion.
jammerdave wrote:Might be worth checking, but I used to have lots of problems with static on the 25K meters causing them to not move, or hang. A bit of static spray on a rag solved it..
Kelly wrote: Isn't the meter on the transmitter pretty much just used as a reference? At least with a tube-final transmitter, assuming your transmitter is tuned and operating correctly, isn't measuring power via the Indirect Method actually preferred?
This is pretty much how everyone does it except for some low power (<1 KW) transmitters which do not reveal Ep or Ip or eqivalent directly. In those cases you can use the power meter if the manufacturer provides calibration info.Kelly wrote:you use the Indirect Method of power calculation: Ep X Ip X published efficiency Factor. Isn't the meter on the transmitter pretty much just used as a reference?
brandonb959 wrote:Are you legally required to have a watt meter on every transmitter? or just required to have the transmitter output meter properly calibrated?
Users browsing this forum: No registered users and 1 guest