I used a Palomar up converter with Drakes in the past and it worked really great. I am going to try and find another one for my 1500. Should be a great combo.
Sent from my iPhone On Feb 23, 2012, at 3:33 PM, "Robert Costa, KB6QXM" <kb6...@yahoo.com> wrote: It is good to see many hams working on this project. As I agree that filtering can eliminate most or all of the images below 1.8 mhz. My only concern is the sensitivity at those frequencies. I am wondering if a up converter would be the best solution. 73, Robert KB6QXM "Ham Radio Open Conversation" Yahoo group owner/moderator ----- Reply message ----- From: "Chuck O'Neal" <cdon...@comcast.net> To: <flexradio@flex-radio.biz> Subject: [Flexradio] 472-479 KHz receiving and transmitting ERP and antennamodels Date: Thu, Feb 23, 2012 12:12 pm Here is what I've done with excellent results for the 600+ meter band. I have two Clifton Labs filters, one is the BCB reject filter mentioned below and a second custom low pass filter I had made by Clifton La bs with a 3 dB corner at 85 0 KHz. This second filter allows my Flex 5000A to cover the low end of the BCB with no images, down to 500 KHz from about 850 KHZ where the images appear to start up pretty badly. As noted by Jordan, the BCB band reject filter still allows stuff from above the BCB to to get in and produce lots of false signals below 500 KHz. I can hear 160M amateur signals there with the BCB reject filter in. When I run both the 830KHz low pass filter and the BCB reject filter in series, ALL the false signals and images go away. Nothing left but actual signals from 500 KHz down to about 250 KHz where images from below 500 KHz begin to start up. I think another low pass filter at around 275 KHz would allow reception down lower yet. With all these filters, I think a down converter is probably best in the end. Chuck K1KW ----- Original Message ----- From: "Jordan" <outposte...@shaw.ca> To: "Lloyd Berg N9LB" <lloydb...@charter.net>, flexradio@flex-radio.biz Sent: Thursday, February 23, 2012 2:42:31 PM Subject: Re: [Flexradio] 472-479 KHz receiving and transmitting ERP and antennamodels I have a Jack Smith customized and swept NDB/Navtex BCB reject filter with the following attenuation specs within the BCB: 770khz -83.127dB 910khz -84.85dB 960khz -83.467dB I have the sweeps for the curious.... When inline, the display above 550khz shows next to nothing, but once you tune below 500khz there are still 'false' signals everywhere, although not as strong as without the filter. Like this, I can hear WWVB quite well, but cannot rely on the signals that appear on the display to be real. It takes a further tunable preselector to clear most but not all of the rest of the 'ghosts', and that only works over a 20-30khz bandwidth at a time. Personally, a good upconverter to one of the ham bands that have BPfiltering @ 50ohms impedance at the input would be a better solution. YMMV...73...Jordan VE6ZT ----- Original Message ----- From: "Lloyd Berg N9LB" <lloydb...@charter.net> To: <flexradio@flex-radio.biz> Sent: Thursday, February 23, 2012 12:19 PM Subject: [Flexradio] 472-479 KHz receiving and transmitting ERP and antennamodels > > I have a 500 KHz low pass filter on the way from Clifton Labs. I will > test 600-630 meter receive capability with the FLEX-5000 and FLEX-1500. > I'll give the group a report once I've had a chance to install it and run > some tests. > > Also, > > Ralph, W5JGV - WD2XSH/7, has "run the numbers" on how much power you will > need in order to generate 1 watt effective radiated power. ( A 50' > vertical, no top loading, will need 102 watts of transmitter output to > generate 1W effective radiated power ). > > Check out the numbers here: http://500kc.com/600_M_Vert_Ant_Chart.htm > > 73 > > Lloyd - N9LB > _______________________________________________ > FlexRadio Systems Mailing List > FlexRadio@flex-radio.biz > http://mail.flex-radio.biz/mailman/listinfo/flexradio_flex-radio.biz > Archives: http://www.mail-archive.com/flexradio%40flex-radio.biz/ > Knowledge Base: http://kc.flexradio.com/ Homepage: > http://www.flexradio.com/ _______________________________________________ FlexRadio Systems Mailing List FlexRadio@flex-radio.biz http://mail.flex-radio.biz/mailman/listinfo/flexradio_flex-radio.biz Archives: http://www.mail-archive.com/flexradio%40flex-radio.biz/ Knowledge Base: http://kc.flexradio.com/ Homepage: http://www.flexradio.com/ _______________________________________________ FlexRadio Systems Mailing List FlexRadio@flex-radio.biz http://mail.flex-radio.biz/mailman/listinfo/flexradio_flex-radio.biz Archives: http://www.mail-archive.com/flexradio%40flex-radio.biz/ Knowledge Base: http://kc.flexradio.com/ Homepage: http://www.flexradio.com/ _______________________________________________ FlexRadio Systems Mailing List FlexRadio@flex-radio.biz http://mail.flex-radio.biz/mailman/listinfo/flexradio_flex-radio.biz Archives: http://www.mail-archive.com/flexradio%40flex-radio.biz/ Knowledge Base: http://kc.flexradio.com/ Homepage: http://www.flexradio.com/ _______________________________________________ FlexRadio Systems Mailing List FlexRadio@flex-radio.biz http://mail.flex-radio.biz/mailman/listinfo/flexradio_flex-radio.biz Archives: http://www.mail-archive.com/flexradio%40flex-radio.biz/ Knowledge Base: http://kc.flexradio.com/ Homepage: http://www.flexradio.com/
