thinking of making the leap from FM to SW

[Pigmeat]

Look for old 60's era Johnson ham band low pass filters at hamfests if you're worried about spurs. They're built like tanks, and have a cap on each end for tweaking. They will handle more power than most of us will think about using, and are dirt cheap. I see them selling in the 5-10 buck range regularly.

They're overkill, but what the hell. Just because the things are in their fifties doesn't mean they won't still do the job.

BTW, didn't the MakeRf guy have a schematic for a simple low pass filter on his blog to complement his tx designs?

[jackson_r]

A related question...the X1M manual warns that if you attempt to use frequencies outside of the main Ham bands, a band pass filter may be required.  I don't know if such a filter is necessary given what I want to do with the setup or not?  

I read that on the spec sheet also.  It sounds like some/all bandpass filtering can be disabled (or is automatically disabled) when selecting a frequency outside ham bands.  Bandpass filtering is there to make sure there are no spurious harmonic emissions unintentionally broadcast along with the target frequency.  Noise and splatter are your enemies, especially when your "Nickelback Marathon" is inadvertently being broadcast over top of some obscure government band.  Assuming that you'll be camping at 6925, you won't run into harmonic issues until like the 70cm band  but that's over 15th order.  

At least educate yourself/be aware of bandpass filtering techniques.  There's tons of good websites and LC calculators:

http://www.electronics-tutorials.ws/filter/filter_4.html

Or just buy one from MFJ for $60.    But at 5W I wouldn't sweat it.  Game on, Wayne.

Curious to hear more reports about this rig.... although all those nights of completely SMOKING FT-101s makes me a little jealous of noobs with no solder skills being able to plunk down $ and get heard... but I digress.  Most of all, HAVE FUN!

Thanks for the added tips, JW.  I've definitely been hearing some good things about the X1M.  Yes, there are a handful of people who say that they're cheap Chinese junk, but the rig has developed such a following that there are actually dedicated discussion forums for X1M enthusiasts.  Unfortunately I don't think I'd be welcome in any of them given how I want to test the unit.  

Finally, yes, I'm one of "those" people.    If I can plunk down $300-$400 for a pre-built unit and get on the air within a few minutes, I'm all about that.  I wouldn't say I'm lazy, it's just that I'm all about efficiency and available time.  I'm fully aware there are plans/kits out there to build Grenades and what-not for a fraction of the cost.  I could try to get myself some better soldering skills, and then it'd take me a couple of weeks of late evenings trying to put everything together.  When it was finally all completed, I'd probably be the guy you read about on the news who got arrested for blasting Benny Goodman over the neighbor's baby monitor.  But the more likely scenario is that it wouldn't work at all and I'd spend another week troubleshooting only to throw the whole damn thing in the trash and go out and order something idiot proof like the X1M.  If there's one constant in life that I firmly believe in, it's that a man has to know his limitations.   

[ff]

But at 5W I wouldn't sweat it.  Game on, Wayne.

JW voiced my feelings underlying all my posts here Jackson.  I would be doing my best to dissuade you from jumping onto the bands with high power before you have a decent understanding about things.  But 5 watts of PEP might get you a few reports here and there, and you shouldn't be pi$$ing off the wrong entities.  Moof voiced another concern of mine about the possible detrimental effects of long keydown periods.  You've gotta keep in mind that most rigs are rated for communications duty.  In other words, a ham might key his mike for maybe a minute at a time and then will be listening for a similar stretch.  But you will be transmitting continuously for much longer than that.  We'll just have to see if the X1M can take that abuse.  One more thing, if you go on to higher power you must have band filtering.  To operate QRO without it is just begging for trouble.  But with 5 watts PEP, probably not.  Have fun, and get some practice soldering, will ya?  You are gonna need it...

[jackson_r]

All points well taken, ff.  If all goes well for a while running at 5 watts out of the box, I've got my eye on a little 45 W QRP amplifier that would give a nice boost.  Before I'd do something like that I'd definitely get a good band pass filter.

[JehovahsWettness]

Finally, yes, I'm one of "those" people.    If I can plunk down $300-$400 for a pre-built unit and get on the air within a few minutes, I'm all about that.  I wouldn't say I'm lazy, it's just that I'm all about efficiency and available time.  I'm fully aware there are plans/kits out there to build Grenades and what-not for a fraction of the cost.  I could try to get myself some better soldering skills, and then it'd take me a couple of weeks of late evenings trying to put everything together.  When it was finally all completed, I'd probably be the guy you read about on the news who got arrested for blasting Benny Goodman over the neighbor's baby monitor.  But the more likely scenario is that it wouldn't work at all and I'd spend another week troubleshooting only to throw the whole damn thing in the trash and go out and order something idiot proof like the X1M.  If there's one constant in life that I firmly believe in, it's that a man has to know his limitations.   

I was fortunate enough to grow up in a military/aeronautical RF environment but as soon as I left the farm I was super tempted by the latest Chinese 5W PLL FM stereo transmitter on e-bay for like $250.  I was sick of dicking with my Dunifer kit transmitter, so I made the plunge.  It was AWESOME and COMPACT.  I mean SMALL.  And when it suddenly smoked itself for no good reason, I had to shitcan it because there were basically 3 SMT SOICs on it with no discernible part numbers.  Would I do it again if I were still into FM?  Prolly.  That xmtr feeding a surplus 300W broadcast amp got me some wicked propagation with a simple home-made J-pole. 

LOL, Dunifer.

You'll catch the bug and realize you have to solder and think about power supplies and junk.  Don't worry.

[jackson_r]

After reading up more on some of the limitations of the X1M, I've decided to follow ff's original advice and go with a used Icom IC-735.  There's lots of info on the diode cutting mod that will open it up for all band transmit and it certainly sounds like it's a lot more solid unit (not to mention the 100 watt power).  A used one is also about $100 cheaper than the X1M.  The X1M is getting sent back once it arrives.   

[ff]

After reading up more on some of the limitations of the X1M, I've decided to follow ff's original advice and go with a used Icom IC-735.  There's lots of info on the diode cutting mod that will open it up for all band transmit and it certainly sounds like it's a lot more solid unit (not to mention the 100 watt power).  A used one is also about $100 cheaper than the X1M.  The X1M is getting sent back once it arrives.   

I've owned two of them over the years - the second one bought on ebay about 7 or 8 years ago.  The diode clip is no big deal.  Don't sweat it.  When this model was first out in the early 90s Icom ballyhooed it as being designed for hour-long keydown times.  Let me assure you- with reasonable care, it will perform admirably for you.  Anteater Radio famously used a 735 to transmit pirate shows from his over-the-road big rig into a MOBILE antenna.  Don't let the small size fool ya... it's robust.  Hopefully you'll get one that's lightly used but if not, the 735 is worth sinking a few more bux into at the local repair shop if its needed.  Good luck to you in your search for a good one....

[jackson_r]

Now you've piqued my interest, ff.  I have a business trip in October that's going to require about 6 hours of driving, roundtrip.  To think I could be broadcasting 6 hours, non-stop, with very little chance of being tracked down.  I might have to go look for a mobile antenna.