From ok1dfc at seznam.cz Mon Aug 5 10:59:47 2019 From: ok1dfc at seznam.cz (Zdenek SAMEK-OK1DFC) Date: Mon, 05 Aug 2019 10:59:47 +0200 (CEST) Subject: [Moon] EME QRT Message-ID: <59g.2DCc.7Pilwi3ocm0.1TH}03@seznam.cz> Hi EME gang, I am temporary QRT on EME. My 10m dish is down and Saturday ast weekend was moved to QTH of Sebastian DG5CST which want to follow up with that antenna via Moon. I hope to return soon with new setup. First will be 24 and 10 GHz 2,5m offset dish. Working on and hope to be QRV up to end of August. Last week in August I am in USA, so will do my best be QRV before. Then I will follow up with 6m professional offset dish used before as satellite uplink on 18GHz. I want to use it for bands from 6 up to 13cm and extended with mesh up to 9m for 23 and 70cm. So I hope to be back on Moon soon. Between, in worse case of missing anything important, I can build immediately my 3,2m portable setup in garden :-) 73! and GL -- Zdenek - OK1DFC www.ok1dfc.com QRV EME 144 MHz - 24 GHz WAC 432 - 1296 - 2320 MHz WAZ #9 - WAS 432 #29 DXCC 432 - 1296 MHz From iw3hvb at gmail.com Mon Aug 12 11:36:30 2019 From: iw3hvb at gmail.com (Giulio IW3HVB) Date: Mon, 12 Aug 2019 11:36:30 +0200 Subject: [Moon] TX7EME back on air in 2020 Message-ID: Hi all, TX7EME will be back on air (call to be confirmed) from Rangiroa atoll, French Polynesia, 18 to 24 June 2020, this time on 23 cm. Me and Corrado IK3YBX will operate a 2 mt dish with good power, ensuring opportunities for both digital and cw QSOs. Windows for Europe at our moonrise (BH65EA) will be fairly short, but with take off on the ocean. We will suggest for the stations to call starting from eastern europe, then for the second part of the window towards north west. G and EI stations will be the last, given the longer common moon acquisition. Further details in the future on my website www.iw3hvb.it Best 73. Giulio IW3HVB From g3ltf at btinternet.com Mon Aug 12 12:10:35 2019 From: g3ltf at btinternet.com (Peter Blair) Date: Mon, 12 Aug 2019 11:10:35 +0100 Subject: [Moon] 432 and above EME Newsletter Message-ID: <2980E9D1E5E6474A98E5899CC6F60F21@PeterKBlairPC5> Al, K2UYH, and Matej, OK1TEH, will be working on the 432 and above EME Newsletter this week. Send all your news, especially about your activity on the Apollo 11 weekend and the 13cm/ 9cm Microwave AW and your contacts with the great Western States dxpedition, together with any technical items, to alkatz at tcnj.edu Previous NL can be found at http://www.nitehawk.com/rasmit/em70cm.html 73 Peter G3LTF From sa6bun at gmail.com Wed Aug 14 13:45:29 2019 From: sa6bun at gmail.com (Michael Kohla) Date: Wed, 14 Aug 2019 13:45:29 +0200 Subject: [Moon] WTB Message-ID: Hi out there, looking for a WR42 termination, preferably with only a short WG run. If somebody is willing to part with such an item for a reasonable price, please contact me off list. 73, Michael From brian at brcg4nns.org Thu Aug 15 12:41:33 2019 From: brian at brcg4nns.org (Brian Coleman) Date: Thu, 15 Aug 2019 11:41:33 +0100 Subject: [Moon] Dish available. Message-ID: Hello Folks I have been made aware of a 2.4m prime focus dish that is available. f/D thought to be 0.4, some mounting hardware available. A photo of it lying face down is available but no other details.  The price is a donation to to the charitable trust that had intended to use it for RA but no longer requires it. I reckon it's a 4 person lift and close vehicle access may be difficult to arrange so a 100m carry could be required. Location Devizes Southern England. Serious enquiries only please to brian at brcg4nns.org. Brian G4NNS From sm2cew at telia.com Sat Aug 17 19:02:44 2019 From: sm2cew at telia.com (Peter Sundberg) Date: Sat, 17 Aug 2019 17:02:44 +0000 Subject: [Moon] PRIZES ARI EME TROPHY 2018 to Ham Radio In-Reply-To: <7f36bd45-a62d-8227-f0e3-b9986d27fe47@i5wbe.it> References: <7f36bd45-a62d-8227-f0e3-b9986d27fe47@i5wbe.it> Message-ID: A couple of weeks ago I received a most beautiful plaque from ARI for the ARI EME Trophy 2018, Autumn Session. The plaque was delivered by ARI (Enrico?) to Swedish friends at the Ham Radio Meeting and eventually it ended up by snailmail in my QTH. Many thanks to the organizer ARI for this fine CW EME event and for the beautiful plaque! 73, ciao! Peter SM2CEW At 10:43 2019-06-17, you wrote: >--- PRIZE WILL BE GIVEN AT HAM RADIO DIRECTLY FRIDAY AT 13.00 IN >FRONT OF QSL WALL OR TO THEIR BUREAU PRESENT AT HAM RADIO >_______________________________________________ Moon mailing list >Moon at moonbounce.info http://moonbounce.info/mailman/listinfo/moon >Join eQSL.cc https://eqsl.cc/qslcard/Index.cfm From ve1kg at eastlink.ca Sat Aug 17 19:27:12 2019 From: ve1kg at eastlink.ca (Serge Szpilfogel) Date: Sat, 17 Aug 2019 14:27:12 -0300 Subject: [Moon] PRIZES ARI EME TROPHY 2018 to Ham Radio In-Reply-To: <20190817170334.8804811A209F@root213.premium-rootserver.net> References: <7f36bd45-a62d-8227-f0e3-b9986d27fe47@i5wbe.it> <20190817170334.8804811A209F@root213.premium-rootserver.net> Message-ID: Comgratulations Peter we worked on cow Serge ve1kg Sent from my iPhone > On Aug 17, 2019, at 14:02, Peter Sundberg via Moon wrote: > > A couple of weeks ago I received a most beautiful plaque from ARI for the ARI EME Trophy 2018, Autumn Session. > > The plaque was delivered by ARI (Enrico?) to Swedish friends at the Ham Radio Meeting and eventually it ended up by snailmail in my QTH. > > Many thanks to the organizer ARI for this fine CW EME event and for the beautiful plaque! > > 73, ciao! > Peter SM2CEW > > > > > > At 10:43 2019-06-17, you wrote: >> --- PRIZE WILL BE GIVEN AT HAM RADIO DIRECTLY FRIDAY AT 13.00 IN FRONT OF QSL WALL OR TO THEIR BUREAU PRESENT AT HAM RADIO _______________________________________________ Moon mailing list Moon at moonbounce.info http://moonbounce.info/mailman/listinfo/moon Join eQSL.cc https://eqsl.cc/qslcard/Index.cfm > > > _______________________________________________ > Moon mailing list > Moon at moonbounce.info > http://moonbounce.info/mailman/listinfo/moon > > Join eQSL.cc https://eqsl.cc/qslcard/Index.cfm From rein0zn at ix.netcom.com Wed Aug 21 06:43:50 2019 From: rein0zn at ix.netcom.com (rein0zn at ix.netcom.com) Date: Tue, 20 Aug 2019 21:43:50 -0700 (GMT-07:00) Subject: [Moon] 432 and Above EME Newsletter for August 2019 Message-ID: <1668486928.16442.1566362631096@wamui-marley.atl.sa.earthlink.net> Hello All, The 432 MHz and Above EME Newsletter for August 2019 by K2UYH can be downloaded from: http://www.nitehawk.com/rasmit/em70cm.html -- Enjoy -- Tnx Al. 73 Rein W6SZ From rein0zn at ix.netcom.com Wed Aug 21 17:57:25 2019 From: rein0zn at ix.netcom.com (rein0zn at ix.netcom.com) Date: Wed, 21 Aug 2019 08:57:25 -0700 (GMT-07:00) Subject: [Moon] Updated 432 and Above EME Newsletter for August 2019 Message-ID: <1197639727.4118.1566403045582@wamui-bison.atl.sa.earthlink.net> Hello All, The 432 MHz and Above EME Newsletter for August 2019 by K2UYH can be downloaded from: http://www.nitehawk.com/rasmit/em70cm.html -- Enjoy -- Tnx Al. 73 Rein W6SZ From per at per-dudek.de Thu Aug 22 12:27:12 2019 From: per at per-dudek.de (Per Dudek) Date: Thu, 22 Aug 2019 10:27:12 +0000 Subject: [Moon] 10ghz beacon Message-ID: hi 10ghz beacon is dead since last night.no output. vy73 per dk7lj From jewell at btinternet.com Thu Aug 22 13:07:07 2019 From: jewell at btinternet.com (jewell at btinternet.com) Date: Thu, 22 Aug 2019 11:07:07 +0000 (UTC) Subject: [Moon] 10ghz beacon In-Reply-To: References: Message-ID: <1476750581.248529.1566472027322@mail.yahoo.com> Is there a facility for the EME community to contribute towards the beacon maintenance? Sam, G4DDK Sent from Yahoo Mail for iPad On Thursday, August 22, 2019, 11:27 am, Per Dudek via Moon wrote: hi 10ghz beacon is dead since last night.no output. vy73 per dk7lj _______________________________________________ Moon mailing list Moon at moonbounce.info http://moonbounce.info/mailman/listinfo/moon Join eQSL.cc  https://eqsl.cc/qslcard/Index.cfm From keith at vk6eme.com Thu Aug 22 16:00:04 2019 From: keith at vk6eme.com (Keith) Date: Thu, 22 Aug 2019 22:00:04 +0800 Subject: [Moon] 10ghz beacon In-Reply-To: <1476750581.248529.1566472027322@mail.yahoo.com> References: <1476750581.248529.1566472027322@mail.yahoo.com> Message-ID: <22C46E4F-EC5C-46A4-8FF4-317B13BF7F0A@vk6eme.com> I’m sure a few of us in VK would love to contribute as we rely so heavily on the beacon, I know I would ) cheers Keith > On 22 Aug 2019, at 7:07 pm, jewell--- via Moon wrote: > > Is there a facility for the EME community to contribute towards the beacon maintenance? > Sam, G4DDK > > > > Sent from Yahoo Mail for iPad > > > On Thursday, August 22, 2019, 11:27 am, Per Dudek via Moon wrote: > > hi > > 10ghz beacon is dead since last night.no output. > > vy73 per dk7lj > > _______________________________________________ > Moon mailing list > Moon at moonbounce.info > http://moonbounce.info/mailman/listinfo/moon > > Join eQSL.cc https://eqsl.cc/qslcard/Index.cfm > > > _______________________________________________ > Moon mailing list > Moon at moonbounce.info > http://moonbounce.info/mailman/listinfo/moon > > Join eQSL.cc https://eqsl.cc/qslcard/Index.cfm keith at vk6eme.com VK6KB / VK6EME 0488 228 088 From per at per-dudek.de Thu Aug 22 17:20:00 2019 From: per at per-dudek.de (Per Dudek) Date: Thu, 22 Aug 2019 15:20:00 +0000 Subject: [Moon] 10 ghz beacon Message-ID: hi thanks all for offering finanzial suport.i do have always the help  in equipment( PA) and knowlege from charlie g3wdg and Michael db6nt.the problems with db6nt pa  before and now with charlies pa is that a permanent full carrier use is quite another thing then normal amateur use.it is not a problem of cooling(watercooled), but a Problem of the material.both pa have worked for more then one year without any Problem.i am very glad to hear that the beacon is used by many oms and that it is imortant for them to have it.the main reason to runn the beacon for me is to motivate amateurs to make their first steps on 10 ghz.for this i can tell you 24ghz beacon is nearly ready.the only not jet solved problem is the transistor pa.it may take some time to find a permanent soluton for the 10ghz pa,but just this is part of our hobby.thanks again for offering financial Support,but there is no need at the moment vy73 per dk7lj From g3ltf at btinternet.com Fri Aug 23 00:13:34 2019 From: g3ltf at btinternet.com (Peter Blair) Date: Thu, 22 Aug 2019 23:13:34 +0100 Subject: [Moon] Microwave activity weekend reminder Message-ID: <23B7C41B0B2043808CC684C786A417D7@PeterKBlairPC5> August 24th is scheduled for 3cm and August 25th for 6cm For newcomers.....an AW is when we attempt to get all those with capability on a specific band to come on and make QSOs, run tests for those needing signals, test new feeds, preamps etc. No pressure, no scoring, use the reflector, use any mode, just activate the band. Hopefully there will be some big guns active. 73 Peter G3LTF From ejespers at telenet.be Sat Aug 24 15:12:08 2019 From: ejespers at telenet.be (Eddy Jespers) Date: Sat, 24 Aug 2019 15:12:08 +0200 Subject: [Moon] ON0EME beacon In-Reply-To: <5D5D4C2C.1060408@gmail.com> References: <607535647.16438.1566362536615@wamui-marley.atl.sa.earthlink.net> <5D5D4C2C.1060408@gmail.com> Message-ID: <1FE1462F-09AA-458A-84CF-8C4A243DC5F5@telenet.be> The power amplifier of the ON0EME beacon failed again. We will try to fix it over the weekend. Hopefully back early next week. 73’s Eddy ON7UN From jewell at btinternet.com Sat Aug 24 15:48:32 2019 From: jewell at btinternet.com (jewell at btinternet.com) Date: Sat, 24 Aug 2019 13:48:32 +0000 (UTC) Subject: [Moon] ON0EME beacon In-Reply-To: <1FE1462F-09AA-458A-84CF-8C4A243DC5F5@telenet.be> References: <607535647.16438.1566362536615@wamui-marley.atl.sa.earthlink.net> <5D5D4C2C.1060408@gmail.com> <1FE1462F-09AA-458A-84CF-8C4A243DC5F5@telenet.be> Message-ID: <1891966147.1458294.1566654512763@mail.yahoo.com> Eddy,I guess the same donation offer should also be made to you guys for all the hard work and materials for such a useful facility.Any need, and if so, how to donate? 73 de Sam, G4DDK Sent from Yahoo Mail for iPad On Saturday, August 24, 2019, 2:12 pm, Eddy Jespers via Moon wrote: The power amplifier of the ON0EME beacon failed again. We will try to fix it over the weekend. Hopefully back early next week. 73’s Eddy ON7UN _______________________________________________ Moon mailing list Moon at moonbounce.info http://moonbounce.info/mailman/listinfo/moon Join eQSL.cc  https://eqsl.cc/qslcard/Index.cfm From ejespers at telenet.be Sat Aug 24 16:46:32 2019 From: ejespers at telenet.be (Eddy Jespers) Date: Sat, 24 Aug 2019 16:46:32 +0200 Subject: [Moon] ON0EME beacon In-Reply-To: <1891966147.1458294.1566654512763@mail.yahoo.com> References: <607535647.16438.1566362536615@wamui-marley.atl.sa.earthlink.net> <5D5D4C2C.1060408@gmail.com> <1FE1462F-09AA-458A-84CF-8C4A243DC5F5@telenet.be> <1891966147.1458294.1566654512763@mail.yahoo.com> Message-ID: Hi Sam, Donations for the beacon are not necessary, this gives us a “ no obligation “ but we try to keep it running. The recurring cost is quite low, only the yearly license fee and the domain registration + ddns are the only costs involved. We do not have to pay for the electricity consumption ( which is significant for this beacon ) as well our IP connection is run by hams and free of charge for us. Keeping the beacon up and running is part of our hobby anyway ;-) This time one of the two drains of the MRF13750H came lose of the output PCB. The copper pad was all rotten and only 1mm of material was left from the device. I just soldered a copper part to the remains of the drain and the output now is only 350 watt with 7 watt drive and 800 watt DC power ( 40 V 20 A ) In the beacon the drive power is slightly higher so there I expect around 400 W I have the amplifier in test now. Hopefully this will hold for some time. I just ordered a new MRF13750H for future repairs or if this repair would fail. In regards of the failed output C’s , Charlie G3WDG suggested to leave out the output C’s and just bridge the parts with a copper bridge. Since the probe in the feed is not DC grounded it is not really a problem to have DC on the output. Paul W1GHZ suggested to replace the ATC’s by short pieces of semi rigid to make the capacitors . I will play with both suggestions tomorrow. Vy 73’s Eddy ON7UN > On 24 Aug 2019, at 15:48, jewell at btinternet.com wrote: > > Eddy, > I guess the same donation offer should also be made to you guys for all the hard work and materials for such a useful facility. > Any need, and if so, how to donate? > > 73 de Sam, G4DDK > > > > Sent from Yahoo Mail for iPad > > On Saturday, August 24, 2019, 2:12 pm, Eddy Jespers via Moon wrote: > > The power amplifier of the ON0EME beacon failed again. We will try to fix it over the weekend. > Hopefully back early next week. > > 73’s Eddy ON7UN > > _______________________________________________ > Moon mailing list > Moon at moonbounce.info > http://moonbounce.info/mailman/listinfo/moon > > Join eQSL.cc https://eqsl.cc/qslcard/Index.cfm From jewell at btinternet.com Sat Aug 24 17:25:33 2019 From: jewell at btinternet.com (jewell at btinternet.com) Date: Sat, 24 Aug 2019 15:25:33 +0000 (UTC) Subject: [Moon] ON0EME beacon In-Reply-To: References: <607535647.16438.1566362536615@wamui-marley.atl.sa.earthlink.net> <5D5D4C2C.1060408@gmail.com> <1FE1462F-09AA-458A-84CF-8C4A243DC5F5@telenet.be> <1891966147.1458294.1566654512763@mail.yahoo.com> Message-ID: <1354686810.1488443.1566660333095@mail.yahoo.com> Thanks Eddy.I think, then, if you do decide that donations are wanted, the community would be only too willing to help. Your description of the problem is interesting. It sounds like a short talk on keeping the beacon running, problems and experiences, would be of interest at EME2020, if you are going? 73 de Sam Sent from Yahoo Mail for iPad On Saturday, August 24, 2019, 3:46 pm, Eddy Jespers wrote: Hi Sam, Donations for the beacon are not necessary, this gives us a “ no obligation “ but we try to keep it running. The recurring cost is quite low, only the yearly license fee and the domain registration + ddns are the only costs involved. We do not have to pay for the electricity consumption ( which is significant for this beacon ) as well our  IP connection is run by hams and free of charge for us. Keeping the beacon up and running is part of our hobby anyway ;-) This time one of the two drains of the MRF13750H came lose of the output PCB. The copper pad was all rotten and only 1mm of material was left from the device. I just soldered a copper part to the remains of the drain and the output now is only 350 watt with 7 watt drive and 800 watt DC power ( 40 V   20 A ) In the beacon the drive power is slightly higher so there I expect around 400 W  I have the amplifier in test now. Hopefully this will hold for some time. I just ordered a new MRF13750H for future repairs or if this repair would fail. In regards of the failed output C’s , Charlie G3WDG suggested to leave out the output C’s and just bridge the parts with a copper bridge. Since the probe in the feed is not DC grounded it is not really a problem to have DC on the output. Paul W1GHZ suggested to  replace the ATC’s by short pieces of semi rigid to make the capacitors .   I will play with both suggestions tomorrow. Vy 73’s Eddy ON7UN On 24 Aug 2019, at 15:48, jewell at btinternet.com wrote: Eddy,I guess the same donation offer should also be made to you guys for all the hard work and materials for such a useful facility.Any need, and if so, how to donate? 73 de Sam, G4DDK Sent from Yahoo Mail for iPad On Saturday, August 24, 2019, 2:12 pm, Eddy Jespers via Moon wrote: The power amplifier of the ON0EME beacon failed again. We will try to fix it over the weekend. Hopefully back early next week. 73’s Eddy ON7UN _______________________________________________ Moon mailing list Moon at moonbounce.info http://moonbounce.info/mailman/listinfo/moon Join eQSL.cc  https://eqsl.cc/qslcard/Index.cfm From charlie at sucklingfamily.free-online.co.uk Sat Aug 24 19:42:02 2019 From: charlie at sucklingfamily.free-online.co.uk (charlie at sucklingfamily.free-online.co.uk) Date: Sat, 24 Aug 2019 18:42:02 +0100 Subject: [Moon] ON0EME beacon In-Reply-To: References: <607535647.16438.1566362536615@wamui-marley.atl.sa.earthlink.net> <5D5D4C2C.1060408@gmail.com> <1FE1462F-09AA-458A-84CF-8C4A243DC5F5@telenet.be> <1891966147.1458294.1566654512763@mail.yahoo.com> Message-ID: Hi Eddy It looks like your recent failure is different to what happened to the DL0SHF 50W GaN PA. In that case the pcb failed midway between the device and the output connector. The device itself was fully functional. The more recent failure again seems to be a pcb failure. I do not know yet if the device is still functional. There is no obvious reason why the pcb substrate failed. In operation the calculated temperature rise of the microstrip carrying the output power is only 20-30C above chassis temp which should be totally benign according to Rogers. There is a Rogers application note that discusses thermal cycling as a cause of cracking due to work hardening of copper. The stresses result from differential thermal expansion of copper to the substrate. Over time the constant stretching and compression forces can lead to failure. I could not prove this with the DL0SHF PA as all that was left was a charred mess on the pcb. The DL0SHF PA had accumulated just under 500 operational hours, with some 30,000 temperature cycles. This kind of operation is atypical of how PAs tend to be used in normal applications, so we are definitely in a learning mode here! I have had some discussions with an LDMOS PA expert who tells a tale of amplifier failures in a digital broadcasting application where the PA ran during the day and was switched off at night (to save energy) and failures of the soldered joint between drain and pcb occurred after only a few months. The solution was to run the PA 24/7, after which no more failures occurred. The theory was that the solder joint was being mechanically stressed due to mechanical expansion/compression. The stress on the solder joint is worse for devices (such as LDMOS or discrete GaAs or GaN transistors) since the joint has to carry both RF and DC currents. The GaN device in the DL0SHF PA has separate DC and RF connections, so the solder joints are less stressed, and do not seem to have failed. Looking at the temperature excursions in more detail, both LDMOS and GaN are operated Class AB so when RF goes on the devices will heat up probably in a few seconds and then cool down when RF goes off. The pcb temperature will rise further due to losses (and probably faster than the device due to the higher thermal resistance). Additionally there will be larger temperature changes when the beacon goes on at the start of the moon pass and off again at the end of the pass. Another possible theory for failure could relate to environmental conditions. If for example a chilled water cooling system is used to cool the PA, when the beacon goes off at the end of a pass the amplifier chassis would end up below ambient temperature and if the dew point of the surrounding air is above that temperature, water could condense on the amplifier, possibly causing corrosion or some other kind of damage when operation is resumed. I have seen such water condensation in the lab when using a chilled water cooling system so it certainly can happen. In a professional lab, chilled water coolers have a case around the amplifier which is flushed with a dry gas to prevent such condensation. I think what we are learning is that beacon operation with PAs that are built 'normally' is a whole different ballgame compared to typical amateur operation! With multiple potential factors at play, and root causes not yet identified I think users will have to accept that from time to time failures are unfortunately inevitable. 73 Charlie From ejespers at telenet.be Sat Aug 24 20:10:05 2019 From: ejespers at telenet.be (Eddy Jespers) Date: Sat, 24 Aug 2019 20:10:05 +0200 Subject: [Moon] ON0EME beacon In-Reply-To: References: <607535647.16438.1566362536615@wamui-marley.atl.sa.earthlink.net> <5D5D4C2C.1060408@gmail.com> <1FE1462F-09AA-458A-84CF-8C4A243DC5F5@telenet.be> <1891966147.1458294.1566654512763@mail.yahoo.com> Message-ID: <66188AEC-B505-4817-BCE2-07FD1346DC12@telenet.be> Hello Charlie, I wonder if we need to chose the correct solder, to solder the devices to the PCB. I have been using Kester SN63 PB37 solder first to solder the device and the output capacitors. Melting temperature for this solder is 183° C Last time I made some changements to the PA I used Cynel SN99,3CUO,7 solder, so lead free and a higher melt temperature ( 227°C ) These solder joints do not look as nice as the Kester joints. For the new repair I used solder paste Chipquik TS391AX ( SN63/PB37 ) to connect the damaged drain pad of the device to a new copper conductor, and soldered the whole with Kester SN63 PB37. In fact, this new solder SN99,3CU0,7 failed at one of the drains of the MRF13750H . Are you aware of any recommendations of solder type being used for these devices ? I now soldered the device again with Kester SN63 PB37 and solder paste SN63/PB37 but I am wondering what to use for the output circuit. Vy 73’s Eddy ON7UN > On 24 Aug 2019, at 19:42, charlie at sucklingfamily.free-online.co.uk wrote: > > Hi Eddy > > It looks like your recent failure is different to what happened to the > DL0SHF 50W GaN PA. In that case the pcb failed midway between the device > and the output connector. The device itself was fully functional. The > more recent failure again seems to be a pcb failure. I do not know yet if > the device is still functional. There is no obvious reason why the pcb > substrate failed. In operation the calculated temperature rise of the > microstrip carrying the output power is only 20-30C above chassis temp > which should be totally benign according to Rogers. There is a Rogers > application note that discusses thermal cycling as a cause of cracking due > to work hardening of copper. The stresses result from differential > thermal expansion of copper to the substrate. Over time the constant > stretching and compression forces can lead to failure. I could not prove > this with the DL0SHF PA as all that was left was a charred mess on the > pcb. The DL0SHF PA had accumulated just under 500 operational hours, with > some 30,000 temperature cycles. This kind of operation is atypical of how > PAs tend to be used in normal applications, so we are definitely in a > learning mode here! > > I have had some discussions with an LDMOS PA expert who tells a tale of > amplifier failures in a digital broadcasting application where the PA ran > during the day and was switched off at night (to save energy) and failures > of the soldered joint between drain and pcb occurred after only a few > months. The solution was to run the PA 24/7, after which no more failures > occurred. The theory was that the solder joint was being mechanically > stressed due to mechanical expansion/compression. The stress on the > solder joint is worse for devices (such as LDMOS or discrete GaAs or GaN > transistors) since the joint has to carry both RF and DC currents. The > GaN device in the DL0SHF PA has separate DC and RF connections, so the > solder joints are less stressed, and do not seem to have failed. > > Looking at the temperature excursions in more detail, both LDMOS and GaN > are operated Class AB so when RF goes on the devices will heat up probably > in a few seconds and then cool down when RF goes off. The pcb temperature > will rise further due to losses (and probably faster than the device due > to the higher thermal resistance). Additionally there will be larger > temperature changes when the beacon goes on at the start of the moon pass > and off again at the end of the pass. > > Another possible theory for failure could relate to environmental > conditions. If for example a chilled water cooling system is used to cool > the PA, when the beacon goes off at the end of a pass the amplifier > chassis would end up below ambient temperature and if the dew point of the > surrounding air is above that temperature, water could condense on the > amplifier, possibly causing corrosion or some other kind of damage when > operation is resumed. I have seen such water condensation in the lab when > using a chilled water cooling system so it certainly can happen. In a > professional lab, chilled water coolers have a case around the amplifier > which is flushed with a dry gas to prevent such condensation. > > I think what we are learning is that beacon operation with PAs that are > built 'normally' is a whole different ballgame compared to typical amateur > operation! With multiple potential factors at play, and root causes not > yet identified I think users will have to accept that from time to time > failures are unfortunately inevitable. > > 73 > > Charlie > > > > > From charlie at sucklingfamily.free-online.co.uk Sun Aug 25 10:26:07 2019 From: charlie at sucklingfamily.free-online.co.uk (charlie at sucklingfamily.free-online.co.uk) Date: Sun, 25 Aug 2019 09:26:07 +0100 Subject: [Moon] [Moon-Net] ON0EME beacon In-Reply-To: References: <607535647.16438.1566362536615@wamui-marley.atl.sa.earthlink.net> <5D5D4C2C.1060408@gmail.com> <1FE1462F-09AA-458A-84CF-8C4A243DC5F5@telenet.be> <1891966147.1458294.1566654512763@mail.yahoo.com> Message-ID: <3351199a7365bcbf65ff5ae3855a133b.squirrel@webmail.plus.net> Hi Paul Given the thermal mass of the elements in the system, I doubt that the temperature is varying significantly during a transmit period as a result of A1 keying. Indeed, DL0SHF uses FSK. The switching system at DL0SHF removes RF and DC from the PA when the transmission ceases partway though a 60s sequence. This I believe is by far the largest contributor to thermal cycling. I believe the switching system was designed this way to prolong the life of the active device (lower average device 'junction' temperature) than having it run continuously. It also allows echoes to be monitored - during the CW sequence the last emission is a steady carrier. At this stage, thermal cycling induced failure is only a theory. Given that these problems only show up after the beacons have been operating some time, feedback about the effectiveness of a 'fix' is somewhat delayed. 73 Charlie > If beacons were keyed with FSK rather than CW, temperature would be pretty > constant. Also easier to peak. There is a 10 Ghz FSK beacon in > Massachusetts that works well with both tones in SSB bandwidth. Use CW > filter to separate > > 73 > paul > > On Sat, Aug 24, 2019, 13:46 Charlie via Moon-net < > moon-net at mailman.pe1itr.com> wrote: > >> Hi Eddy >> >> It looks like your recent failure is different to what happened to the >> DL0SHF 50W GaN PA. In that case the pcb failed midway between the >> device >> and the output connector. The device itself was fully functional. The >> more recent failure again seems to be a pcb failure. I do not know yet >> if >> the device is still functional. There is no obvious reason why the pcb >> substrate failed. In operation the calculated temperature rise of the >> microstrip carrying the output power is only 20-30C above chassis temp >> which should be totally benign according to Rogers. There is a Rogers >> application note that discusses thermal cycling as a cause of cracking >> due >> to work hardening of copper. The stresses result from differential >> thermal expansion of copper to the substrate. Over time the constant >> stretching and compression forces can lead to failure. I could not prove >> this with the DL0SHF PA as all that was left was a charred mess on the >> pcb. The DL0SHF PA had accumulated just under 500 operational hours, >> with >> some 30,000 temperature cycles. This kind of operation is atypical of >> how >> PAs tend to be used in normal applications, so we are definitely in a >> learning mode here! >> >> I have had some discussions with an LDMOS PA expert who tells a tale of >> amplifier failures in a digital broadcasting application where the PA >> ran >> during the day and was switched off at night (to save energy) and >> failures >> of the soldered joint between drain and pcb occurred after only a few >> months. The solution was to run the PA 24/7, after which no more >> failures >> occurred. The theory was that the solder joint was being mechanically >> stressed due to mechanical expansion/compression. The stress on the >> solder joint is worse for devices (such as LDMOS or discrete GaAs or GaN >> transistors) since the joint has to carry both RF and DC currents. The >> GaN device in the DL0SHF PA has separate DC and RF connections, so the >> solder joints are less stressed, and do not seem to have failed. >> >> Looking at the temperature excursions in more detail, both LDMOS and GaN >> are operated Class AB so when RF goes on the devices will heat up >> probably >> in a few seconds and then cool down when RF goes off. The pcb >> temperature >> will rise further due to losses (and probably faster than the device due >> to the higher thermal resistance). Additionally there will be larger >> temperature changes when the beacon goes on at the start of the moon >> pass >> and off again at the end of the pass. >> >> Another possible theory for failure could relate to environmental >> conditions. If for example a chilled water cooling system is used to >> cool >> the PA, when the beacon goes off at the end of a pass the amplifier >> chassis would end up below ambient temperature and if the dew point of >> the >> surrounding air is above that temperature, water could condense on the >> amplifier, possibly causing corrosion or some other kind of damage when >> operation is resumed. I have seen such water condensation in the lab >> when >> using a chilled water cooling system so it certainly can happen. In a >> professional lab, chilled water coolers have a case around the amplifier >> which is flushed with a dry gas to prevent such condensation. >> >> I think what we are learning is that beacon operation with PAs that are >> built 'normally' is a whole different ballgame compared to typical >> amateur >> operation! With multiple potential factors at play, and root causes not >> yet identified I think users will have to accept that from time to time >> failures are unfortunately inevitable. >> >> 73 >> >> Charlie >> >> >> >> >> >> _______________________________________________ >> Moon-Net posting and subscription instructions are at >> http://www.nlsa.com/nets/moon-net-help.html >> >> > _______________________________________________ > Moon-Net posting and subscription instructions are at > http://www.nlsa.com/nets/moon-net-help.html > > From charlie at sucklingfamily.free-online.co.uk Sun Aug 25 10:53:52 2019 From: charlie at sucklingfamily.free-online.co.uk (charlie at sucklingfamily.free-online.co.uk) Date: Sun, 25 Aug 2019 09:53:52 +0100 Subject: [Moon] [Moon-Net] ON0EME beacon In-Reply-To: <66188AEC-B505-4817-BCE2-07FD1346DC12@telenet.be> References: <607535647.16438.1566362536615@wamui-marley.atl.sa.earthlink.net> <5D5D4C2C.1060408@gmail.com> <1FE1462F-09AA-458A-84CF-8C4A243DC5F5@telenet.be> <1891966147.1458294.1566654512763@mail.yahoo.com> <66188AEC-B505-4817-BCE2-07FD1346DC12@telenet.be> Message-ID: <3694d8ea76472a127e4f2acb41be3bed.squirrel@webmail.plus.net> Hi Eddy I generally use 62Sn36Pb2Ag solder paste (Alpha OM-5100 'no clean') or a wire solder of the same composition. Its also an approx 185C solder. I've seen differing comments about the Ag content regarding embrittlement and thermal cycling. I will ask my LDMOS expert for his comments, but this may take a few days. I would recommend using 63Sn37Pb solder for the moment. 73 Charlie > Hello Charlie, > > I wonder if we need to chose the correct solder, to solder the devices to > the PCB. I have been using Kester SN63 PB37 solder first to solder the > device and the output capacitors. Melting temperature for this solder is > 183° C > Last time I made some changements to the PA I used Cynel SN99,3CUO,7 > solder, so lead free and a higher melt temperature ( 227°C ) These > solder joints do not look as nice as the Kester joints. > > For the new repair I used solder paste Chipquik TS391AX ( SN63/PB37 ) to > connect the damaged drain pad of the device to a new copper conductor, and > soldered the whole with Kester SN63 PB37. > > In fact, this new solder SN99,3CU0,7 failed at one of the drains of the > MRF13750H . > > Are you aware of any recommendations of solder type being used for these > devices ? I now soldered the device again with Kester SN63 PB37 and > solder paste SN63/PB37 but I am wondering what to use for the output > circuit. > > Vy 73’s Eddy ON7UN > > >> On 24 Aug 2019, at 19:42, charlie at sucklingfamily.free-online.co.uk >> wrote: >> >> Hi Eddy >> >> It looks like your recent failure is different to what happened to the >> DL0SHF 50W GaN PA. In that case the pcb failed midway between the >> device >> and the output connector. The device itself was fully functional. The >> more recent failure again seems to be a pcb failure. I do not know yet >> if >> the device is still functional. There is no obvious reason why the pcb >> substrate failed. In operation the calculated temperature rise of the >> microstrip carrying the output power is only 20-30C above chassis temp >> which should be totally benign according to Rogers. There is a Rogers >> application note that discusses thermal cycling as a cause of cracking >> due >> to work hardening of copper. The stresses result from differential >> thermal expansion of copper to the substrate. Over time the constant >> stretching and compression forces can lead to failure. I could not prove >> this with the DL0SHF PA as all that was left was a charred mess on the >> pcb. The DL0SHF PA had accumulated just under 500 operational hours, >> with >> some 30,000 temperature cycles. This kind of operation is atypical of >> how >> PAs tend to be used in normal applications, so we are definitely in a >> learning mode here! >> >> I have had some discussions with an LDMOS PA expert who tells a tale of >> amplifier failures in a digital broadcasting application where the PA >> ran >> during the day and was switched off at night (to save energy) and >> failures >> of the soldered joint between drain and pcb occurred after only a few >> months. The solution was to run the PA 24/7, after which no more >> failures >> occurred. The theory was that the solder joint was being mechanically >> stressed due to mechanical expansion/compression. The stress on the >> solder joint is worse for devices (such as LDMOS or discrete GaAs or GaN >> transistors) since the joint has to carry both RF and DC currents. The >> GaN device in the DL0SHF PA has separate DC and RF connections, so the >> solder joints are less stressed, and do not seem to have failed. >> >> Looking at the temperature excursions in more detail, both LDMOS and GaN >> are operated Class AB so when RF goes on the devices will heat up >> probably >> in a few seconds and then cool down when RF goes off. The pcb >> temperature >> will rise further due to losses (and probably faster than the device due >> to the higher thermal resistance). Additionally there will be larger >> temperature changes when the beacon goes on at the start of the moon >> pass >> and off again at the end of the pass. >> >> Another possible theory for failure could relate to environmental >> conditions. If for example a chilled water cooling system is used to >> cool >> the PA, when the beacon goes off at the end of a pass the amplifier >> chassis would end up below ambient temperature and if the dew point of >> the >> surrounding air is above that temperature, water could condense on the >> amplifier, possibly causing corrosion or some other kind of damage when >> operation is resumed. I have seen such water condensation in the lab >> when >> using a chilled water cooling system so it certainly can happen. In a >> professional lab, chilled water coolers have a case around the amplifier >> which is flushed with a dry gas to prevent such condensation. >> >> I think what we are learning is that beacon operation with PAs that are >> built 'normally' is a whole different ballgame compared to typical >> amateur >> operation! With multiple potential factors at play, and root causes not >> yet identified I think users will have to accept that from time to time >> failures are unfortunately inevitable. >> >> 73 >> >> Charlie >> >> >> >> >> > > > _______________________________________________ > Moon-Net posting and subscription instructions are at > http://www.nlsa.com/nets/moon-net-help.html > > From g0ruz at g0ruz.com Wed Aug 28 15:49:15 2019 From: g0ruz at g0ruz.com (Conrad PA5Y) Date: Wed, 28 Aug 2019 13:49:15 +0000 Subject: [Moon] Fibox lid screws - spares? In-Reply-To: <15BF1695D7BB5C37.26882@groups.io> References: <15BF1695D7BB5C37.26882@groups.io> Message-ID: I use quite a few Fibox IP65 enclosures and one of them had the lid screws missing when it was delivered. I bought it from Conrad electronics and they replaced the whole box. So I have a box with no lid screws. I would like to use it but I cannot find these screws anywhere. Farnell don't seem to have them, Conrad don't have them. An email to the Dutch Fibox distributor was ignored. Does anyone know where I can get them? 73 Conrad PA5Y _._,_._,_ From sm4ive at telia.com Fri Aug 30 18:52:37 2019 From: sm4ive at telia.com (sm4ive) Date: Fri, 30 Aug 2019 18:52:37 +0200 Subject: [Moon] Weinheim Ukw Message-ID: If all goes well we plan to go to Weinheimhope to see some EME rs73 Lars SM4IVESkickat från min Samsung Galaxy-smartphone.