August 2020 - AMSAT-BB - mailman.amsat.org

fuses
by mikflathead＠aol.com 13 Aug '20

13 Aug '20

There are 2 fuses behind the ac power connector. They are 5 amp 250 volt. They are a bout 3/16 diameter and 3/4 inch long. I do not see them on a schematic. Mike

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FT-736 update.
by Bill Acito 12 Aug '20

12 Aug '20

How do you know there are additional fuses besides the one on the case? I took a look, and as you said, nothing in the schematics or in a general google search. b

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FT-736 update.
by Vince Fiscus, KB7ADL 12 Aug '20

12 Aug '20

Hi All, Still working on the 736. When the PS went, it blew all three fuses. There is a 4 amp external fuse, but there are two internal fuses that were also blown. I can't find the internal fuses on any of the schmaticz. Does any know the current rating of the internal fuses? The rig is okay, it was the power supply that blew the fuses. Thanks again KB7ADL

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Tom’s Show Last Sunday
by Clint Bradford 12 Aug '20

12 Aug '20

Great job, Tom, at the online QSO Extravagana! Videos from the event are posted for another week or so … If you missed Tiom LIVE, you can watch the recording. www.qsotodayhamexpo.com Clint K6LCS work-sat.com Sent from my iPhone

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Re: [amsat-bb] 70cm LNA
by Zach Metzinger 12 Aug '20

12 Aug '20

On 08/12/20 14:26, Kevin Elliott wrote: > Not wanting to use this with a transceiver, mostly just for my 70cm QFH with SDR for satnogs. Aware of any other 70cm and 2m LNAs that perform well for receive-only? Hello Kevin, I've heard good things about LNA4ALL (https://lna4all.blogspot.com/), which has a high IIP3 and low NF. The +33dBm IIP3 would help with overload issues on the LNA itself, but the high gain (+23dB) would then overload your SDR/rig with those, now amplified, high-power out-of-band signals. If you added an appropriate filter, such as the one I used, to the output, then you'd have a good solution. --- Zach N0ZGO

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Cubesat Design Specification update call for review
by Bruce Perens 12 Aug '20

12 Aug '20

Cal Poly wants feedback for their new spec at https://static1.squarespace.com/static/5418c831e4b0fa4ecac1bacd/t/5f24997b6… "The original CDS introduced the CubeSat Standard to the world almost two decades ago. It defined the physical and electrical characteristics for a 1U and 3U size CubeSat and included requirements for interfacing with the only CubeSat dispenser available at the time, the Poly-Pico Orbital Deployer (P-POD). Since then the industry has expanded to include more standard sizes and additional dispensers with more available options. To accommodate these new advancements, the CDS has been retooled to be more flexible and inclusive of developments within the industry. Requirements that were originally written specifically for the P-POD will encompass requirements for all dispensers currently available. It is also the intention for the new revision of the CDS to identify the available options on dispensers that are widely available for use. Currently that list is limited to dispensers that publish their specifications online, but can be updated as dispenser companies make that information available to us. The CDS will also define all U configurations in one document with one set of requirements for ease of reference."

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Another mailing list?
by Michael B 12 Aug '20

12 Aug '20

I thought I had subscribed to the digest version of this list, but apparently I subscribed to the drama version. Is there a mailing list that focuses on the technical aspects of amateur satellite use? For example, I would like to know of SSTV events and other operational aspects. I don't care to know about infighting of AMSAT members and officers. Does anyone have some suggestions? Thank you in advance. Michael

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Re: [amsat-bb] 70cm LNA
by Zach Metzinger 12 Aug '20

12 Aug '20

On 08/12/20 13:54, Kevin Elliott wrote: > Are there any complete built filters to inline by chance from any retailer? Hello Kevin, I do not know of anyone offering this filter, and it isn't something you'd want to transmit through. I don't even know how much power it would survive before releasing the magic smoke (probably < 1W). The SAW filter is on the output of the LNA chip, so it is switched out during TX. You could take your LNA apart and tack this in to achieve the same effect. You'd laugh at the component-on-it's-side soldering job with 30ga wire-wrap wire, but it works! I plan to lay out a board and release it to the community with build instructions. However, I have another project or two in front of that before I have free time. --- Zach N0ZGO

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ME to HI for WAS--Possible at present?
by Wes Baden 11 Aug '20

11 Aug '20

Any ideas about the following? My QTH is in Maine, FN54, 120 feet ASL. I'm closing in on WAS, but the problem is going to be Hawaii. From my rough calculations, I need a SAT that has a 4500+ mile footprint, meaning an apogee of 1200+ miles, and even then any operating window will be pretty short. Current MEO satellites do not seem to offer a window quite that big, or am I missing something? In theory, I guess, I could go to Mt. Washington, NH (fortunately only 90 miles away) and a KH6 could go up on a volcanic peak there, to try to make use of over-the-horizon signal bending. But I'm not sure if even that would work at the present time, and in any case I can wait if a better MEO or an HEO bird is in the offing in the next few years. Does anyone know if ME-HI will be possible in the future, and if so when? WAS SAT is on my bucket list. Of course I envy all of you to the west of me, who can contact HI, but on the other hand it is nice to be only 3200 or so from London, 3800 miles from Berlin. We are all prisoners of our locations, at least until another HEO satellite is in orbit again. Thanks for feedback. And by the way, I'm always happy to sked with anyone needing FN54, not the rarest grid in ME but a challenge for many stations, especially out west or so they tell me. 73, Wes NA1ME

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RS Satellite Robot
by Gary 11 Aug '20

11 Aug '20

A question came up on Facebook about a QSL from a satellite. I remember some of the RS Satellites carried a 'Robot' which would QSO you with a serial number. You could then send that information to Box 88 in Moscow and receive a QSL. A quick Google search did not turn up any pictures of the cards. I would love to see one, and I am sure they are out there. Anyone have any links? 73, Gary "Joe" kk0sd

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