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GET /hyperkitty/api/list/[email protected]/email/DQQHC6MWUFESC3W3IR4OCQUKWRVWZK6E/
{ "url": "https://mailman.amsat.org/hyperkitty/api/list/[email protected]/email/DQQHC6MWUFESC3W3IR4OCQUKWRVWZK6E/", "mailinglist": "https://mailman.amsat.org/hyperkitty/api/list/[email protected]/", "message_id": "[email protected]", "message_id_hash": "DQQHC6MWUFESC3W3IR4OCQUKWRVWZK6E", "thread": "https://mailman.amsat.org/hyperkitty/api/list/[email protected]/thread/SAI57MQQES5IBWHIDU52TN6BGZTXLN2I/", "sender": { "address": "zleffke (a) vt.edu", "mailman_id": "57a24afb1cf641f98121841e6753c12e", "emails": "https://mailman.amsat.org/hyperkitty/api/sender/57a24afb1cf641f98121841e6753c12e/emails/" }, "sender_name": "Zach Leffke", "subject": "Re: [amsat-bb] Best Mast mount PA/LNA?", "date": "2015-06-04T23:27:52Z", "parent": "https://mailman.amsat.org/hyperkitty/api/list/[email protected]/email/FFCIMCYO3TQN4RWKBXI7LID3YOYI6XXC/", "children": [], "votes": { "likes": 0, "dislikes": 0, "status": "neutral" }, "content": "Bob,\n\nFor LNAs:\nI'll throw in a vote for ARR as well. I personally own both their \nreceive only pre-amps and the model referenced in the link below for \n2m/70cm. The VT amateur radio club has used them in the past as well \n(and will be again in the near future). Additionally, the big ground \nstation we are building at VT (separate from the amateur radio club, \ncalling it the VTGS) will also be using them on 2m, 70cm, and for the \nNOAA 137MHz birds. I have had great success with them.\n\nI did a massive survey to try to answer this question for the VTGS \ndesign and finally settled on the ARR devices. Down East Microwave and \nKuhne Electronics were high on the list, but they only sell RX only \npre-amps, requiring you to come up with your own solution for the \nbypassing/sequencing for TX. I think M2 Antennas has an option or two, \nbut they are super high quality and super expensive (I think geared more \ntowards kW operations and EME work). The models referenced KB1PVH below \nhave a built in RF Sense circuit for automatically switching for TX \noperations, but if you are like me and nervous about the RF sense stuff \nfailing and cooking your pre-amp, they have a PTT signal built in for \nuse with an external sequencer. They can handle up to 160W when in TX \nstate. For the quality of the product (RX performance, and weather \nproof mast mountable), ease of use on TX (rf sense or ptt), and the \nprice point, ARR was the way to go for us. One final bump for them is \ntheir customer service. I discussed this with them during my survey for \nthe VTGS design and they basically said that if you accidentally cook \none of their pre-amps, the cost to repair it is minimal (not much more \nthan the cost of shipping).\n\nFor PAs:\nI also did a big survey to try to answer this question as well. The \noptions I looked at included some designs from W6PQL based on the \nmitsubishi RF MOSFET modules (with the right filtering!!!, \nwww.w6pql.com), the designs from Down East Microwave based on the MOSFET \nmodules (no filtering though), some commercial broad-band amps that \ncover 2m/70cm, the very common Mirage brick amps, and finally Kuhne \nElectronics (out of Germany). For the VTGS we have a bit different \nsetup that uses SDRs on the backend instead of traditional HW radios. \nThe devices we are using (Ettus USRPs with WBX/SBX daughterboards) only \nput out about 100mW max output on the Amateur Satellite bands. So I \nneeded to get from about 100mW to about 100W and ensuring that I meet \nFCC limits for out of band performance. I finally settled on some \nproducts from Kuhne Electronics that can achieve full drive of 60W with \nabout 10mW on the input and have built in filtering to meet FCC limits.\n\nIf your looking for a mast mounted PA, you might want to consider the \nMitsubishi RF Modules (be careful about harmonics, and out of band \nemissions!) and the designs from W6PQL. He also offers some good \nfilters that provide (1) the required suppression for out of band \nemssions and (2) RF detection ports for monitoring fwd/rev power \nlevels. This could be a fairly compact design that could be integrated \ninto a weatherproof enclosure and mounted on the mast. Its not a canned \nsolution that you can just buy though. Someone would have to do the \ndetailed design work, and then actually build everything, I'm just \nthrowing it out there as an idea.\n\nIt sounds like the simplest \"swap option\" to replace your existing \nhardware might be the Mirage amps (http://www.mirageamp.com/). They \nhave built in pre-amps, can get you up to around 160W or so on 2m \n(model: B-1018-G) and 100W on 70cm (model: D-1010-N) with about 10W \ndrive, have the TX/RX circuitry built right in, and have the right \nfiltering. I have only ever used them with the manual ssb/fm switch, so \nfor mast mounting I think they have a remote control head that can be \nused to pick which mode your in from the schack (instead of going up on \nthe roof and flipping the ssb/fm switch). It sounds like you might be \nable to directly replace your existing gear with these devices, and it \nmight be the easiest route. Maybe some of these with better weather \nproofing (they're not designed for outdoor use), and maybe better \ncooling (though at low duty cycle use like packet, that might not be \nmuch of a concern).\n\nEven though the Mirage amps have built in pre-amps, I'd still think \nabout putting the ARR gear inline closer to the antennas and using \nsequencers, they are really good performers on RX.\n\n\n-Zach, KJ4QLP\n\nOn 6/4/2015 12:01 PM, David L Warnberg wrote:\n> I can second that, I have them on my egg beaters and they work very well..\n>\n> David KK4QOE\n>\n> -----Original Message-----\n> From: AMSAT-BB [mailto:[email protected]] On Behalf Of Dave Webb\n> KB1PVH\n> Sent: Thursday, June 04, 2015 10:04 AM\n> To: Bob Bruninga\n> Cc: AMSAT -BB\n> Subject: Re: [amsat-bb] Best Mast mount PA/LNA?\n>\n> Bob,\n>\n> I've had good luck with ARR preamps.\n>\n> http://www.advancedreceiver.com/page10.html\n>\n> Dave-KB1PVH\n>\n> Sent from my Samsung S4\n> _______________________________________________\n> Sent via [email protected]. AMSAT-NA makes this open forum available to all\n> interested persons worldwide without requiring membership. Opinions\n> expressed are solely those of the author, and do not reflect the official\n> views of AMSAT-NA.\n> Not an AMSAT-NA member? Join now to support the amateur satellite program!\n> Subscription settings: http://www.amsat.org/mailman/listinfo/amsat-bb\n>\n> _______________________________________________\n> Sent via [email protected]. AMSAT-NA makes this open forum available\n> to all interested persons worldwide without requiring membership. Opinions expressed\n> are solely those of the author, and do not reflect the official views of AMSAT-NA.\n> Not an AMSAT-NA member? Join now to support the amateur satellite program!\n> Subscription settings: http://www.amsat.org/mailman/listinfo/amsat-bb\n\n\n", "attachments": [] }