Hi Russ totally in agree with you, switching on/off the preamp will tell you not only the noise increment, will tell you if your antenna system is good or not BUT always compare with the same measurement with a 50 ohms dummy load on the preamp input, a standard well design EME system has this 50 ohms dummy on the top, even the VK3UM software simulate the presence to do the properly calculations, another story is related with the noise around you, if your backyard is to noisy in that case your location is not good for EME and you need to accept the limitation in terms on how much you can go deep on the noise to pickup a EME signal, is a matter of luck, I know people with location were not even birdies are in the pass band and they have a fantastic reception, other ones are in the middle of a city with high noise, accept the compromise and improve as much as possible or try to move your station to another location are the only options. Regarding the excess of antenna noise, well to keep low, you need very good designs and good assembling skills about connectors and cables, if your antenna temperature is to high becouse the design is not good enought you cannot do nothing to solve that problem, I think plenty of information exist in internet about that topic. 73 de Alex, HB9DRI From: Russ K2TXB [mailto:k2txb@dxcc.com] Sent: Sonntag, 27. Januar 2013 02:48 To: 'Alex Artieda'; 'Ian McCloy'; moon-net(a)nlsa.com Subject: RE: [Moon-Net] FT-736R vs TS-2000 Hello Alex. I agree with what you are saying and that brings up an issue that I think should be reviewed. You and Leif, and probably others, are telling people that turning off the head end preamp should result in about 16 db noise drop, but you do not specify how to control excess antenna noise. I think you should tell people to install a 50 ohm load at the preamp input before making that test. That will assure that there is sufficient gain, and they are not adding excess antenna noise to the calculation. Many people live in areas with terrible noise on 2 meters these days and I have heard many stories by people who cannot understand why they cannot hear EME signals even though they are easily being heard by others. Sometimes it is hard to get them to understand what they must do to measure how much excess noise is in their environment. Installing a second antenna relay, with the input switched to load during transmit, when antenna relay is unpowered, allows the gain measurement we are speaking of, and also allows one to compare received noise level against the noise generated by the load. If one is lucky, the load will produce more noise than the antenna, but most of us must live with the opposite condition much of the time. Very rarely I am able to see less noise from the antenna than from the load... 73, Russ K2TXB _____ From: moon-net-bounces(a)mailman.pe1itr.com [mailto:moon-net-bounces@mailman.pe1itr.com] On Behalf Of Alex Artieda Sent: Saturday, January 26, 2013 2:57 PM To: 'Ian McCloy'; moon-net(a)nlsa.com Subject: Re: [Moon-Net] FT-736R vs TS-2000 Hi Ian I just want to tell you something is not correct in your station, when we install together the IQ+ in your antenna system you have 15dB noise increment when we switch on/off the preamp, and this value is not correct due the fact is not possible to reach that values on the IQ+ with just 19dB gain preamp as you declare. As a designer of the IQ+ to have 15dB noise increment you will need at least 24dB gain BUT if you reach that noise increment value (15dB noise increment with only 19dB preamp gain) as I observe remotely then definitive your antenna temperature IS TO HIGH, I insist, something is wrong there, maybe a connector, a splitter or coax but again is not possible to reach 15dB noise increment on the IQ+ with just 19dB preamp, only possible with a noise antenna system, in that case you are trying to resolve your problems just on the radio side and not in the antenna..and this is wrong. 73 de Alex, HB9DRI From: moon-net-bounces(a)mailman.pe1itr.com [mailto:moon-net-bounces@mailman.pe1itr.com] On Behalf Of Ian McCloy Sent: Samstag, 26. Januar 2013 19:31 To: moon-net(a)nlsa.com Subject: [Moon-Net] FT-736R vs TS-2000 Hi All Thanks for the input on these two radios Just to let all know I have always run a mast mounted lna designed by VE7BQH .25nf/19db which has worked very well for me on EME I think for a comparison i will get the TS-2000 receive modified as per Russ K2TXB just to try to see if there is any difference between the 736r and my TS-200 Hope to some comparisons to report over the next month or so Thanks Ian VA7SW//VE7IRA BTW when working EME I have on WSJT the RX DB set to 0 when I turn per amp off there DB on WSJT goes to -15 so the pre amp is definitely working

Hi Ed. Why do you want to unpower your preamp when transmitting? It is not safer for the preamp. Having enough relay isolation is the only formula for preserving your preamp. Regards, Russ K2TXB _____ From: Edward R Cole [mailto:kl7uw@acsalaska.net] Sent: Sunday, January 27, 2013 4:56 AM To: Russ K2TXB; 'Alex Artieda'; 'Ian McCloy'; moon-net(a)nlsa.com Subject: Re: [Moon-Net] FT-736R vs TS-2000 Although I agree, implementing measurements is non-trivial if TR switching selects the 50-ohm termination in Tx mode. In my system the preamp is powered-off in Tx mode and transverter switched to Tx. So for me to make receiver measurements looking into the 50-ohm termination I have to defeat keying of the transverter (easy enough by removing key line). But also I will have to jumper 12v onto preamp wiring to keep preamp powered. All of these are under control of the sequencer in normal operation. I have a manual switch to key the sequencer into Tx mode (which will connect preamp to 50-ohm term). Forgeting any of this will lead to erroneous readings. 73, Ed - KL7UW At 05:48 PM 1/26/2013, Russ K2TXB wrote: Hello Alex. I agree with what you are saying and that brings up an issue that I think should be reviewed. You and Leif, and probably others, are telling people that turning off the head end preamp should result in about 16 db noise drop, but you do not specify how to control excess antenna noise. I think you should tell people to install a 50 ohm load at the preamp input before making that test. That will assure that there is sufficient gain, and they are not adding excess antenna noise to the calculation. Many people live in areas with terrible noise on 2 meters these days and I have heard many stories by people who cannot understand why they cannot hear EME signals even though they are easily being heard by others. Sometimes it is hard to get them to understand what they must do to measure how much excess noise is in their environment. Installing a second antenna relay, with the input switched to load during transmit, when antenna relay is unpowered, allows the gain measurement we are speaking of, and also allows one to compare received noise level against the noise generated by the load. If one is lucky, the load will produce more noise than the antenna, but most of us must live with the opposite condition much of the time. Very rarely I am able to see less noise from the antenna than from the load... 73, Russ K2TXB _____ From: moon-net-bounces(a)mailman.pe1itr.com [ <mailto:moon-net-bounces@mailman.pe1itr.com> mailto:moon-net-bounces@mailman.pe1itr.com] On Behalf Of Alex Artieda Sent: Saturday, January 26, 2013 2:57 PM To: 'Ian McCloy'; moon-net(a)nlsa.com Subject: Re: [Moon-Net] FT-736R vs TS-2000 Hi Ian I just want to tell you something is not correct in your station, when we install together the IQ+ in your antenna system you have 15dB noise increment when we switch on/off the preamp, and this value is not correct due the fact is not possible to reach that values on the IQ+ with just 19dB gain preamp as you declare. As a designer of the IQ+ to have 15dB noise increment you will need at least 24dB gain BUT if you reach that noise increment value (15dB noise increment with only 19dB preamp gain) as I observe remotely then definitive your antenna temperature IS TO HIGH, I insist, something is wrong there, maybe a connector, a splitter or coax but again is not possible to reach 15dB noise increment on the IQ+ with just 19dB preamp, only possible with a noise antenna system, in that case you are trying to resolve your problems just on the radio side and not in the antenna..and this is wrong. 73 de Alex, HB9DRI From: moon-net-bounces(a)mailman.pe1itr.com [ <mailto:moon-net-bounces@mailman.pe1itr.com> mailto:moon-net-bounces@mailman.pe1itr.com] On Behalf Of Ian McCloy Sent: Samstag, 26. Januar 2013 19:31 To: moon-net(a)nlsa.com Subject: [Moon-Net] FT-736R vs TS-2000 Hi All Thanks for the input on these two radios Just to let all know I have always run a mast mounted lna designed by VE7BQH .25nf/19db which has worked very well for me on EME I think for a comparison i will get the TS-2000 receive modified as per Russ K2TXB just to try to see if there is any difference between the 736r and my TS-200 Hope to some comparisons to report over the next month or so Thanks Ian VA7SW//VE7IRA BTW when working EME I have on WSJT the RX DB set to 0 when I turn per amp off there DB on WSJT goes to -15 so the pre amp is definitely working _______________________________________________ Moon-Net posting and subscription instructions are at http://www.nlsa.com/nets/moon-net-help.html

Hi Leif. I do understand that the impedance change into the antenna could cause the gain to change, but I still think (from experience) that it is a worthwile test. At my home location now, When it is very quiet, I can see a db or so less noise from the antenna than from the load [note]. That is where I want to set my gain level because I want my system to perfrom best when I can hear the best. Overload problems can be handled with post preamp attenuation when necessary. 73, Russ K2TXB [note]: At other times, and in certain directions I can see up to 10 db increase in noise compared to the resistor. Then I have to wait for the moon to move to a quieter location - that is easier than moving my station to a quieter location instead, hi hi. -----Original Message----- From: moon-net-bounces(a)mailman.pe1itr.com [mailto:moon-net-bounces@mailman.pe1itr.com] On Behalf Of Leif Asbrink Sent: Sunday, January 27, 2013 6:58 AM To: moon-net(a)nlsa.com Subject: Re: [Moon-Net] FT-736R vs TS-2000 Hi Russ, Alex and all, Correct. I advocate this test for making sure that the noise floor originates in the preamp/ antenna and not in other blocks further down the signal path. It is a general rule valid on all bands. I always write this has to be done with the antenna towards quiet sky. It is NOT a test for the antenna performance. That is another thing and I do not think the comparison with a 50 ohm resistor is safe. That is a valid test only if one knows that VSWR is very good or that the amplifier gain does not change much on source impedance changes. I think it is more safe to study galactic sources and to map the noise floor in different directions. More safe but far more time consuming.... There is no point in having 16 dB noise reduction on a 50 ohm dummy load if one has 25 dB noise reduction on the antenna. In such a case one should reduce gain to get a better dynamic range. To compare with a 50 ohm dummy to get the real antenna temperature is a separate test as I see it. If impedances are well under control it becomes a reliable test (radiometer) and one sould observe about 1 dB less noise from the antenna than from the resistor on 144 MHz maybe nearly 1.5. noise level against the noise generated by the load. Yes, One thing is to design the Rx to fit the antenna. Another thing is to ensure that the antenna is good. One has to do both things:-) load... That means that your rx noise floor is higher than necessary most of the time. In case you have dynamic range problems due to fellow 144 operators you could reduce gain without any loss at all until you reach about 16 dB for the preamp test. Gain reduction does of course not solve the antenna/environment problem, but it could solve other problems... 73 Leif / SM5BSZ _______________________________________________ Moon-Net posting and subscription instructions are at http://www.nlsa.com/nets/moon-net-help.html

John, Gerard and Willi Cngrts very nice job !! Hope next time you all will be able to QSO. 73s Jac, PA3DZL -----Oorspronkelijk bericht----- Van: moon-net-bounces(a)mailman.pe1itr.com [mailto:moon-net-bounces@mailman.pe1itr.com] Namens John Lambo Verzonden: zondag 7 april 2013 10:56 Aan: moon-net(a)mailman.pe1itr.com Onderwerp: [Moon-Net] First RX test from PA0BAT and PA7JB Hello Lunatics. Today Gerard PA0BAT and me did our first rx test on 24ghz with Willi LX1DB. At around 07.10 utc we did hear Willi 529 from the moon. The wheater at Gerard home was a bit foggy and at my home some clouds. Moonnoise at Gerard was 1,2 db because off the fog. My moonnoise was and this cannot be beter for now 1,2 to 1,3 db . Thank you again Willi for your time and we hope to work you soon from the moon on 24ghz. 73 from PA0BAT and PA7JB _______________________________________________ Moon-Net posting and subscription instructions are at http://www.nlsa.com/nets/moon-net-help.html ----- Geen virus gevonden in dit bericht. Gecontroleerd door AVG - www.avg.com Versie: 2013.0.3272 / Virusdatabase: 3162/6229 - datum van uitgifte: 04/06/13

Hi again Alex - OOPS, I should have read your next email before I composed my reply... 73, Russ K2TXB _____ From: moon-net-bounces(a)mailman.pe1itr.com [mailto:moon-net-bounces@mailman.pe1itr.com] On Behalf Of Alex Artieda Sent: Saturday, January 26, 2013 3:05 PM To: 'Ian McCloy'; moon-net(a)nlsa.com Subject: Re: [Moon-Net] FT-736R vs TS-2000 Importance: High Hi Ian: I forgot one thing, you can test the real noise increment if you install a 50 ohms dummy load on the preamp input instead of your antenna, then you will see the real noise increment value, to have the finial value you need to rest 1dB because the Boltzmann constant is different at room temperature (1dB difference). 73 de Alex, HB9DRI From: moon-net-bounces(a)mailman.pe1itr.com [mailto:moon-net-bounces@mailman.pe1itr.com] On Behalf Of Ian McCloy Sent: Samstag, 26. Januar 2013 19:31 To: moon-net(a)nlsa.com Subject: [Moon-Net] FT-736R vs TS-2000 Hi All Thanks for the input on these two radios Just to let all know I have always run a mast mounted lna designed by VE7BQH .25nf/19db which has worked very well for me on EME I think for a comparison i will get the TS-2000 receive modified as per Russ K2TXB just to try to see if there is any difference between the 736r and my TS-200 Hope to some comparisons to report over the next month or so Thanks Ian VA7SW//VE7IRA BTW when working EME I have on WSJT the RX DB set to 0 when I turn per amp off there DB on WSJT goes to -15 so the pre amp is definitely working