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#1
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I just bought a few of these for myself and friends. None of them
seem to be working. I have emailed RMITALY and am waiting for a response. They draw 180ma whether on or off. When driven with 3 watts AM into a 50 ohm dummy load, it draws 500ma (whether on or off) but has no RF output. An SWR meter shows very high SWR between the radio and the amp. With the amp out of the circuit, I see 1.0 SWR and 3 watts on the meter. With power to the amp off, and 3 watts AM in, there is no RF out. Three KL40's I've tested are doing the same thing. Is it possible they switched the wiring to the PL-259's for a big run of these? Anyone seen this problem with KL40's? Ken (to reply via email remove "zz" from address) |
#2
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On Thu, 26 Feb 2004 17:40:40 GMT, Ken wrote:
Is it possible they switched the wiring to the PL-259's for a big run of these? Ooops. I meant SO-239's. Ken (to reply via email remove "zz" from address) |
#3
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#4
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On Thu, 26 Feb 2004 17:40:40 GMT, Ken wrote:
I just bought a few of these for myself and friends. None of them seem to be working. I have emailed RMITALY and am waiting for a response. They draw 180ma whether on or off. When driven with 3 watts AM into a 50 ohm dummy load, it draws 500ma (whether on or off) but has no RF output. An SWR meter shows very high SWR between the radio and the amp. With the amp out of the circuit, I see 1.0 SWR and 3 watts on the meter. With power to the amp off, and 3 watts AM in, there is no RF out. Three KL40's I've tested are doing the same thing. Is it possible they switched the wiring to the PL-259's for a big run of these? Anyone seen this problem with KL40's? Ken (to reply via email remove "zz" from address) Is this your amp? http://www.rmitaly.com/download/manu...al_rel_300.pdf |
#5
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On Thu, 26 Feb 2004 17:40:40 GMT, Ken wrote:
I just bought a few of these for myself and friends. None of them seem to be working. I have emailed RMITALY and am waiting for a response. They draw 180ma whether on or off. When driven with 3 watts AM into a 50 ohm dummy load, it draws 500ma (whether on or off) but has no RF output. An SWR meter shows very high SWR between the radio and the amp. With the amp out of the circuit, I see 1.0 SWR and 3 watts on the meter. With power to the amp off, and 3 watts AM in, there is no RF out. Three KL40's I've tested are doing the same thing. Is it possible they switched the wiring to the PL-259's for a big run of these? Anyone seen this problem with KL40's? Ken (to reply via email remove "zz" from address) http://www.rmitaly.com/download/inst...nstruction.pdf |
#7
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#8
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![]() One other oddity. Before I power up the radio, the amp is drawing zero current. As soon as I power up the radio (on RX), the amp starts drawing 180 ma, whether it is switched on or off. Impossible. The amp has no input for the powered condition of the radio (receive). Do you have the coax in-out connected backwards? |
#10
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On Thu, 26 Feb 2004 20:58:19 -0800, Frank Gilliland
wrote: In , wrote: One other oddity. Before I power up the radio, the amp is drawing zero current. As soon as I power up the radio (on RX), the amp starts drawing 180 ma, whether it is switched on or off. Impossible. The amp has no input for the powered condition of the radio (receive). Wrong -- it's very possible. That is a MOSFET amp with no power switch. A bad combination to be sure, because as long as there is source-drain voltage, any kind of signal can drive it to some extent. It's possible that C1 could be shorted (after all, it's only rated for 50 volts) and the output of the radio have a DC component. Or if D2 is blown (a 1N4148 passing 3 watts -- yikes!) D1 will hold a nice, steady DC bias on the MOSFET. There are a lot of possible scenarios for what he is describing. What -is- impossible is for you to think before you demonstrate your ignorance. Haven't we been through this before, Tnom? Didn't you learn anything the first dozen times? But hey, it's a cheap and crappy amp, and you get what you pay for. Do you have the coax in-out connected backwards? You have your brain connected backwards. Quit trying to act like you know what you are talking about. I stand by my post. There is no voltage on the radios coax on receive that will activate the amps increase in current draw. You should pay more attention. Even if there was a DC voltage C1 on the amp would block it. "You have your brain connected backwards. Quit trying to act like you know what you are talking about." I just couldn't resist. http://www.rmitaly.com/download/inst...nstruction.pdf |
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