[Moon-net] LNA 144 ATF54143? *Peter Hansen* PH at Focon.dk /Mon May 29 01:04:22 CDT 2006/ * Previous message: [Moon-net] LNA 144 ATF54143? <005303.html> * Next message: [Moon-net] LNA 144 ATF54143? <005352.html> * *Messages sorted by:* [ date ] [ thread ] [ subject ] [ author ] ------------------------------------------------------------------------ Hello EME'rs I use a ATF54143 preamp. And I had havily problems getting it to perform correctly. I own a calibrated Noisfigure setup Hp8970a with a HP346 5dB noisesource. I tried to get the RL up on the input side. But when I get RL up I get bad Noisfigures. I Do not know how those guys claiming 0,1- to 0,2dB Nf. I can get a noisefigure of 0,4dB tops and a gain of 20dB. RL on input side is around 5dB tops. With other words I agree totally on RL match on input side, does NOT coincide with optimum NF. I think I know the failure of the guys claiming the very low figures. They use 15dB Noise sources. This gives an easy error as the preamps has bad RL on input. A mismatch gives room for transformation and therefore Error in measured level. I even saw negative figures when using a 15dB source. 73 from OZ1LPR NOTE: This e-mail is intended only for the named recipient(s) above and may contain information that is proprietary, confidential and/or exempt from disclosure under applicable law. If you are not the intended recipient, any disclosure or actions taken as a result of the information in this email is prohibited and may be unlawful. If you have received this message in error, or are not the named recipient(s), please immediately notify the sender via e-mail or call +45 73422500 and delete this e-mail message. ------------------------------------------------------------------------ * Previous message: [Moon-net] LNA 144 ATF54143? <005303.html> * Next message: [Moon-net] LNA 144 ATF54143? <005352.html> * *Messages sorted by:* [ date ] [ thread ] [ subject ] [ author ] ------------------------------------------------------------------------ More information about the Moon-net mailing list