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Ken, I have 2313's and to be honest I meant to drop them in the care package I sent you, but I was stoned on my pain meds and forgot    Say the word and I'll drop them in the mail (free of Course)

wa2mze wrote:

I downloaded the info on the AVR dev kit.  If nothing else it will make a nice vfo for a 20 meter QRP rig I'm hatching in my head.  I found two IF filters in the junk box that I pulled out of some old CB rigs a few years ago.  Both are in the 11 MHZ area (~10.7 and ~11.2 MHZ actually).  Also have the carrier rocks that mate with them, but only have the USB crystal for the 10.7 MHZ filter.  The rig I have in mind is loosely based on this one from June 1963 QST: "A, Solid-State SSB Transceiver" by W3TLN (replace all devices with IC's such as NE602, MC1350, etc).

I've already wound the toroids for the dev board dds lpf.  Also have a good selection of LCD displays and rotary encoders.  I'll probably build the DDS as a module so I can experiment with different xcvr ciruits.

The one thing I don't like about the avr-dev board is the tiny2313 chip (which I don't have anyway).  So I found a 20pin header and will attach an SMD MEGA32 to it 'dead bug' style to plug into the dev board.  I'll also change out the 10.24mhz crystal to a 16mhz.  I won't be able to use all of the io pins on the mega32, but at least I'll have the extra rom/ram and be able to use GCC.  I would have used a Mega324 except that I already have a bunch of Mega32's in SMD.   Of course the mega324 will clock to 20mhz and the mega32 only to 16.

you should have 3 by midweek

wa2mze wrote:

Thanks, guess I'll give them a try.  I tried to dead bug one of the mega32,s and managed to bend every other pin up so I could get a soldering iron in there.  But I broke off one of the pins trying to solder to it.  Problem was routing the wire wrap wire around to the header pulls on the chip lead (which is weaker than the wire).   I do have a break out PC board to mount the smt chips on but it's half the size of the dev board.

20 dollar N3ZI DDS on ebay, looks like the one I have, nice price http://cgi.ebay.com/N3ZI-DDS-KIT-50MHz- … 20af1c1466

thats for the old version, it looks like his new version tunes ALOT better, he has a You Tube video on ebay with his new model and it looks like it performs well

Last edited by W4GNS (2010-01-26 22:05:04)

Tis' true, but as he states, the chip can be ordered for free as a sample, and the other parts most homebrewers would have in the junk box, its a good price

wa2mze wrote:

That $20 DDS that he is selling on ebay is a bare bone unit without the DDS chip.  It's tempting only since I have a sample AD9832 chip.  His new DDS uses the AD9834, which is the same one that 'diz is going to use in his upcoming DDS vfo.

Naw, I'm not thinking of getting the BB model, as I bought one last spring, which as stated in other threads I really don't like, BUT ! I did order the new DDS-2  :-)  I watched his You Tube video and was impressed, him posted that video was the only reason I bought it though, trhe new model has some very nice features in my humble opinion, just got an email from him, so should be here by Saturday.
As you may have figured out I'm steering clear of Atmel in favor of Microchip, so I hope you can put that stuff to good use, thats why I sent it, sooner or later you will use it

wa2mze wrote:

Gary, I got the chips in the mail today.  Thanks.  If you are thinking of buying that $20 DDS board, I have a sample AD9832 I could give you.  It's small enough that I can drop it in an envelope (in anti static foam) and send it for just one first class stamp (I'll pay the postage).
AD has cut down on their samples offing due to the economy.  You can probably still BS them into sending you a sample now and then, but there are more hoops to jump through today than there were a year or two ago.

Why do I get the impression that you REALLY like that DZ radio, Ken  ;-)     On on the Atmel versus Microchip, I'm not and never will be in a postion to decide which is better of the two, I'm just a hobbyist programmer that is self teching himself .Buts its enjoyable BTW, I made the IF Amp Mod to my K3 about days ago, and now I have to undo the mod as I have 20/S9 power line noise on 40 meters with the preamp off, its a SMD resistor that needs to be changed, I sure hate pushing my luck with my K3, but the first removal went well, I just cut the resistor in half, and then removed it

wa2mze wrote:

Ok Gary, sounds like you have things under control.  The AVR and PIC microcontrollers are both good performers often a toss up which one to use.  I like the mega AVR family because they can be programmed in 'C' (winavr GNU complier) which is a lot easier than Assembler.  Using C has it's disadvantages, you full.  Guess he uses the same part for both because the pin out is the same and by buying more of the same part he gets a good price break).

Last edited by W4GNS (2010-01-28 09:15:24)

Lenoard, It very obvious that you do not know me very well   I could touch Mt Rushmore, and it would crumble

kc0wox wrote:

W4GNS wrote:

its a SMD resistor that needs to be changed, I sure hate pushing my luck with my K3, but the first removal went well, I just cut the resistor in half, and then removed it

A really easy way to remove an smd part is to use 2 soldering irons. You can set them on each end of the part and when the solder melts, lift the part up or usually, I've had the part just stick to one of the irons. It's really easy and you won't damage anything.
Leonard

I ruined a board not more than 2 days ago, by usung solder wick, I pulled the trace off the board, so for alot of people I don't think thats the best route to go, Ken you must remember, you're a Pro on such matters, some of use or not     I think for most beginners or hobbist the cut the componet then remove is the most idiot proof route to go, there are some Pros that use this forum, Ken, Lenoard, and Diz to name what I'm aware of, but also some non-pro's (guess who) that would come out better to use the most consersative approch. That is a nice rig that I just ruined by pulling the trace off of and its all SMT

wa2mze wrote:

I use solder wick to remove SMD parts.  The wick will get up 95-99% of the solder and then just  a bit more heat will remove the part.  Resistors and transistors (two or three leads) remove easy, IC's with many pins still require a third or fourth and to pull up on the part (with a small probe) while heating.  Guess that's where those hot air tools come in handy.

The DZ radio looks interesting, but in truth your K2 and K3 will perform better.  I hope he comes out with some smaller less expensive kits later on.

I'd hardly consider myself a pro on soldering SMT stuff.  With BOTH near and far sidedness (can you say bifocals?) and less that rock solid grip (my hands are not THAT shaky, but it's still impossible to keep a soldering tip within 1mm for very long) I have to resort to various aids such as a magnifier or binocular microscope and a support to lean my soldering iron hand against.  Unsoldering is an art (and usually a bit of luck).  Your choice, you can save the part or the board, but usually NOT both!  If you don't remove all the solder and pull up on the part there is always the risk of pulling up a trace or a via.  Cheap circuit boards, or multiple passes of soldering and unsoldering on the same spot, or using too much heat, will destroy the bond between the board and the copper.  If you use a soldering station with an adjustable temperature iron set it to the lowest possible temperature to melt the solder (probably less than 750 degrees).  Fiberglass boards will hold up better than plastic or paper based ones.  Solder wick has to be heated enough to suck up the solder without soldering the wick to the board.  That's how you pull up traces.  You must remove the wick the instant you've removed the heat, once it starts to cool it will stick to the board!  Sometimes a hotter iron or gun is safer to use with the wick than a colder one for the above reason.  Also solder wick comes in different sizes, the use of the right size helps.  The smaller wick will remove solder from fine traces with less risk of damage.  The thicker wick is needed for through hole parts where you have to suck up solder through vias from both sides of the board.  Pure copper wick is the best, instead of tinning it first rub on some paste flux to help it suck up the solder.  Some wick comes pre fluxed.  Oh and don't use ACID flux sold for soldering copper pipes!

wa2mze wrote:

I'd hardly consider myself a pro on soldering SMT stuff.  With BOTH near and far sidedness (can you say bifocals?) and less that rock solid grip (my hands are not THAT shaky, but it's still impossible to keep a soldering tip within 1mm for very long) I have to resort to various aids such as a magnifier or binocular microscope and a support to lean my soldering iron hand against.  Unsoldering is an art (and usually a bit of luck).  Your choice, you can save the part or the board, but usually NOT both!  If you don't remove all the solder and pull up on the part there is always the risk of pulling up a trace or a via.  Cheap circuit boards, or multiple passes of soldering and unsoldering on the same spot, or using too much heat, will destroy the bond between the board and the copper.  If you use a soldering station with an adjustable temperature iron set it to the lowest possible temperature to melt the solder (probably less than 750 degrees).  Fiberglass boards will hold up better than plastic or paper based ones.  Solder wick has to be heated enough to suck up the solder without soldering the wick to the board.  That's how you pull up traces.  You must remove the wick the instant you've removed the heat, once it starts to cool it will stick to the board!  Sometimes a hotter iron or gun is safer to use with the wick than a colder one for the above reason.  Also solder wick comes in different sizes, the use of the right size helps.  The smaller wick will remove solder from fine traces with less risk of damage.  The thicker wick is needed for through hole parts where you have to suck up solder through vias from both sides of the board.  Pure copper wick is the best, instead of tinning it first rub on some paste flux to help it suck up the solder.  Some wick comes pre fluxed.  Oh and don't use ACID flux sold for soldering copper pipes!

I agree with almost all of this. The exception is I feel I'm a better than average solderer. Thats not because I'm good, that is a part of it, but I have some very good equipment. I use a binocular microscope, 8-80 power and it lets me see exactly when the solder changes from solid to liquid. I also have solder wick that is very fine. I don't remember the exact size but it is about the same size of the trace I am working with. I use a temperature controlled solder station and run around 750 degrees. For large solder removal, I use a solder sucker and then switch to a small size solder wick. The best procedure though is to use 2 soldering irons to remove the part then use solder wick under the microscope to remove the excess solder. The resolder operation is under the microscope using .015" solder to limit the amount applied back to the circuit board.

What is important is to not overheat the trace. The copper is stuck on with an epoxy and too much heat will destroy the bond.
Leonard

Looks like Papa Diz has posted his Freq Counter http://www.kitsandparts.com/freqctr.php      when he says February he MEANS February

Last edited by W4GNS (2010-02-01 16:18:52)

Why is everyone so quiet ?  2 questions, I have built the N3Zi DDS, one for me and one for a club memeber, the DDS is very cool by the way and works as advertised, I'm getting them pakaged up, but I'm not happy with the knobs I have on hand so I'm going to order a couple  I would prefer a bigger knob and if I could find one with a dimple it would be better, anyone have any favorites and there preferred supplier ?  I really like this DDS so I want it to look pretty    Also can anyone suggest a chemical that most would have around home to clean up circiut boards (remove flux)  thanks for any comments that you may share