Questions can arise here. First, what kind of wattmeter, with what accuracy level is he using. Is in an RMS or peak reading unit? Makes a difference. Where is he measuring the power.
On my Mastr II 440 repeater, I show maybe 105 watts from the PA to a good dummy load. I am using a Bird 43 with a 100 watt UHF slug. Two cans in the TX path (Decibel) and the power drops to about 70 watts. that figures to be about 0.75 Db loss per can. Not sure, but i recall the specs come out to 1.5 Db insertion loss for the model. Lowest insertion loss per can I know of is maybe 0.5 Db per can. I have a pair of VHF Decibel cans, and they can be adjusted from 0.5 to 3.0 Db insertion loss by adjusting the couplers. That is per can. My Motorola Trash Cans are set at 1.0 Db per can (called trash cans because of their size). What is the rated power output of the transmitter in question, and what is the insertion loss. Is there a true reading on the wattmeter? Note that forward power can sometimes read higher than true if there is more reflected power. Supply voltage to the PA can cause higher power output if higher than specs call for. And having a poor match between the unit and the load can make it look like more power. And to answer something that one person came up with a while back, decreasing the reflected power does not add it to the true radiated power. Actually, if you have 100 watts forward reading, and 5 reflected, the actual radiated is more like 95 watts, minus feed line loss. people forget to take feed line loss into account. YMMV Wayne WA2YNE On Tue, 03 Jun 2008 16:20:40 -0500, Nate Duehr <[EMAIL PROTECTED]> wrote: Snipped > You know -- now that he mentions it... > > 120W *AFTER* the duplexer on a four-can set? I don't believe those > numbers work. > > The receivers in the Icom repeaters are not very selective, and they're > quite sensitive. I bet that setup will desense the snot out of itself. > > But curious if I'm wrong... how? > > How much isolation is that Telewave 4-can set at VHF? > > Nate WY0X > -- Using Opera's revolutionary e-mail client: http://www.opera.com/mail/ ------------------------------------ Yahoo! Groups Links <*> To visit your group on the web, go to: http://groups.yahoo.com/group/Repeater-Builder/ <*> Your email settings: Individual Email | Traditional <*> To change settings online go to: http://groups.yahoo.com/group/Repeater-Builder/join (Yahoo! ID required) <*> To change settings via email: mailto:[EMAIL PROTECTED] mailto:[EMAIL PROTECTED] <*> To unsubscribe from this group, send an email to: [EMAIL PROTECTED] <*> Your use of Yahoo! Groups is subject to: http://docs.yahoo.com/info/terms/
