The AM Rally REALLY STARTS **Friday** (3/31) at 8:00PM !

Discussion in 'Amplitude Modulation' started by WA1QIX, Mar 30, 2017.

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  1. K5UJ

    K5UJ Ham Member QRZ Page

    Not sure they're wing nuts; maybe just want a QSO without 10 breakers. I can cruise a band pretty quickly with the gear driven CR88. Turn on the BFO and roll it down the band listening for heterodynes.

    Balanced feed for balanced antenna: center fed dipole. no balun at the feedpoint. AM doesn't seem to co-exist with baluns all that well, except for a link coupled network which is sort of a tunable balun.
     
  2. K5UJ

    K5UJ Ham Member QRZ Page

    p.s.
    I wish someone would make a box with a power supply, on off switch, power LED, and an antenna jack or jacks, monitor jack, and USB for keyboard and mouse. Inside a raspberry pi or some other minimal processor on a board, running firmware coded SD receiver. I don't give a flip about updates, transmitting, and all that other junk. just a box for 200 bucks I can power up, connect a monitor and mouse and antenna and keyboard too, and speaker, forgot about that, and have a hard coded SD receiver. I'd buy one of those even though it would probably be impossible for me to work on if it crapped out. I don't have anything against having a fish finder; I just don't want to have to !@#$%^& with a computer and I have no interest in paying a thousand dollars for a lot of stuff I don't want or need. That Icom box everyone is ga ga about is a SDR in a box, but it is way too expensive and they didn't even think to put in a video driver and monitor jack on the back so you can use it with a decent size display.
     
  3. K4KYV

    K4KYV Premium Subscriber Volunteer Moderator QRZ Page

    If everything else fit into a small box with a video driver, I could hang a fairly large flat-screen monitor on the blank wall over my operating desk where it would be more like a map or poster, and wouldn't take up space or be in the way. The last thing I need is a keyboard, mouse and pad cluttering up the operating table; it would undoubtedly get covered in clutter and I wouldn't be able to find it or put my hands on it when I needed it anyway. It should be easy enough to make a SDR receiver with panadaptor that used knobs and slider controls and no mouse or keyboard. Maybe a number pad on the front of the box. Another thing is that the thing would have to be RF quiet. Every computer I have ever owned has put out buzzies and birdies somewhere in the spectrum.
     
  4. N1BCG

    N1BCG Ham Member QRZ Page

    Full size monitors with touch screen technology are perfect for that. They're becoming popular in b'cast studios.

    There are also the large iPads and Tablets which could control a receiver via Bluetooth...
     
  5. WA1QIX

    WA1QIX Ham Member QRZ Page

    Hi Don, I have the same problem in my shack - NO ROOM on the operating desks for a keyboard or mouse..... So I had to solve the problem because I need a computer for logging, modulation monitor and operating the SDR....

    I made a shelf under the operating bench that slides in and out and on this are the keyboard and mouse. There is also enough space (about 3.5 inches) between the top of the shelf and the bottom of the top of the operating bench, so it is possible to type without sliding the shelf out all the way. Albeit, you cannot see the keyboard unless it's out all the way, but if you can touch type, you don't usually look at the keyboard anyway.

    Monitor? No space for a monitor either.... so took an old 19 inch flatscreen and mounted it in one of the table racks that is on the operating bench. The computers are in this rack, behind the monitor. There is very little extra space in the operating position, so everything's got to fit in the rack.

    RF hash? Many computers produce this. Easy to fix - take the power supply apart and add a filter comprised of a type 43 ferrite wound with 5 or 6 turns of twisted pair between the line input and the rest of the supply (the AC goes through this) and a cap to ground on each side of the AC line where it enters the power supply case. Completely kill all interference.

    The computer is a wonderful tool in the shack. It significantly enhances (at least my) operating convenience, and provides functions (such as the SDR) which simply cannot be duplicated by any other means. Just integrate the computer into the overall shack scheme like all the other pieces of equipment, and all will be well :cool:
     
  6. K5UJ

    K5UJ Ham Member QRZ Page

    how often do you have to buy a new computer? how often does the current one crap out? What do you do when it does? How much do they cost?
     
  7. WA1QIX

    WA1QIX Ham Member QRZ Page

    Wow, I haven't bought a new computer is MANY years for any purpose. The current computers in the shack are discards (were going to be "recycled" by a customer), but are perfectly usable for shack purposes so I grabbed them. They are old Dells, dual core at around 2.1Ghz running XP. Not the fastest things on earth, but they run PowerSDR, the Modulation Monitor and my logging programs all at the same time just fine. I use one of the computers for everything just mentioned, and the other is strictly for remote controlling the station and handling the audio transport over the Internet.

    But, about 6 months ago, I did pick up a Dell 9020 i7 (4770) machine with 16 gigs of ram, a SSD and Win 7 Pro off Ebay for $399 - used, of course, but in excellent condition. This is my main development machine and not in the shack. That is a real nice computer for sure! F A S T !! The SSD and the i7 along with all that memory really helps things fly along. It takes literally 7 seconds to completely boot up from a cold start.

    Good computing doesn't have to be at all expensive, and of course the shack machines were free. I put an SSD into the main shack machine. That sped things up a lot and for short money too.
     
  8. WA1QIX

    WA1QIX Ham Member QRZ Page

    Oh, I didn't mention what I do if the shack machine craps out... depends on what the problem is. Computers are pretty reliable hardware-wise, and as a rule if you keep things cool, they will last a REALLY long time (sometimes 10 years or more). The most common failures are fans followed by power supplies and then mechanical hard drives. All of those things are fairly straight-forward to correct. If I have the parts kicking around, and the machine is otherwise still good enough to do what it's supposed to do, I'll fix it. If I've got a better machine around, or if the problem will take a long time to fix for little return, I'll swap in a newer machine.

    I suppose its like any other piece of equipment in the shack, or in the house for that matter. I had a 12V 20A switching supply I built around 10 years ago crap out a couple of months ago, and I have to say I just didn't feel like fixing it - time better spent on other things, so I swapped in a modern 12V switcher I had. It's smaller and works better. The dishwasher died a couple of years ago - it was one I had installed in 1993, and I had fixed it a number of times in the past. This time was enough - went out and got a new Bosch (wow is that QUIET!).

    Everyone's different. For me personally, I'd much rather build something new than fix something that's existing. Failures often point to design deficiencies which are often hard to correct. Usually easier to start over with a better design (at least that's the excuse :p )

    Regards, Steve
     
  9. K5UJ

    K5UJ Ham Member QRZ Page

    XP is now out of date with security vulnerabilities. Not everyone has "customers" they can get free Dell boxes from. I guess if your idea of fun is jacking with computers instead of ham gear then that's wonderful, but that's not everyone's dream ham time. Also, I don't know how anyone does development on a Windows machine anyway. You're in a DOS command line environment and I guess if you are comfortable with that and familiar with whatever languages compile there okay, but I have always found it clunky and intolerable. The majority of hams must think computers are FUN whee hee!! :p because most hams don't spend 50 hours or more / week sitting in front of monitors, fooling with software for a living for the past 30 years. I do, and if I had one in the shack I'd barf. I'll be happy to take one of your free boxes out to a target range though ;)
     
  10. N2DTS

    N2DTS Ham Member QRZ Page

    My I5 computer cost me $220.00 and has never had any updates.
    You do not need to care about security if its an sdr computer, mine runs no program other then sdr and the mod monitor and is not normally hooked up to the internet.
    Most people have old computers around, from their kids or just out of date ones that would work fine for an sdrplay rsp2.
    I do not have a keyboard hooked up to the computer, just the mouse.

    [​IMG]

    The computer is up and working before the tubes warm up. That is an older picture, but its the same computer and screen.
    Small form factor computer, they make them even smaller then that.
    I have an old 4 core (amd) computer I used to use, got it new at walmart for $300.00 that has all the sdr software on it as well, and it worked fine for the flex radios, the Anan 10e and other sdr receivers. Its just been sitting on the shelf for years....

    Its fine if you do not want to mess with this stuff, but you are missing out on a fantastic tool.
    I think its very easy, buy used computer (no bloatware), hook up to the internet and download any programs you need, and never hook up the internet again unless you want new software.
    I come down to the shack, turn the master switch on, push the button on the computer, open a program (PSDR) and the mod monitor program and away I go.
    No updates, no keyboard.
     

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