Sunday, April 28, 2013

Diffuser and LED confusion

Front panel with diffuser and LCD
During the front panel build you are going to eventually arrive at the diffuser and LCD installation. This I have found to be one of the more confusing parts and I have seen many questions asked about this process on the Elecraft reflector. Lets start with the diffuser, you will notice each side of this device is covered in a white plastic. Our first impression is to peal it off or at some point it will be pealed off......DO NOT PEAL OFF THIS COATING....this coating stays on and does not come off at all. The diffuser has to be mounted
Diffuser
not flat against the PC board but 1/8 of an inch above the board. To do this locate the small PC board you used to mount the push-buttons onto the front panel. At one end of this PC board you are able to snap off (being very careful) 4 pieces that are going to be used for the spacers of the diffuser. The Elecraft instructions tell you to use elastics to hold the diffuser in place. This is a great method and has worked very well for me. The soldering of the diffuser has to be done on the top of the board as U1 is on the other side of the board. The only caution is to watch where your soldering iron is while soldering the
Diffuser spacers
diffuser pins. You don't want to melt any of the components with the hot soldering iron shaft. After soldering the spacers are removed and the diffuser will be 1/8 off the board.......it's Elecraft magic!!
Now it's time to mount the LCD and again this has a white plastic on the bottom....DO NOT PEAL OFF THIS COATING.....this has to stay on and be careful as I have found it has a tendency to want to come off. Elecraft is very very clear if you peal this off the LCD will not work and it's not covered under warranty. Now you will notice (and are told in the Elecraft manual) a clear plastic film on the top of the LCD for the time being just leave it alone. They do mention also that a clear protective film could be on the bottom of the LCD as well (I have not come across that) but if it's there it has to come off....BUT NOT THE WHITE PLASTIC.....Make sure the LCD is flat against the diffuser before soldering all the pins and these pins also are soldered on the top of the board. Be aware of where your soldering iron is while doing this as to not damage any other components. Once this is done you have mounted the diffuser and LCD!  

White plastic on LCD
diffuser spacers

Monday, April 22, 2013

Front panel is on the bench

Switches added to front panel board
The boss keeps a close eye
I have now moved onto the Panel board and this involves some steps were you have to take your time...or....you may end up redoing things! With this board things start to take shape in the form of what looks like a radio. The push buttons are mounted in this stage and Elecraft has offered up a tool to allow you to seat each switch so it's level and the proper height as well. Take your time here and make sure all is well before the final soldering of each switch. If you ordered the Rework internal Mic adapter (which I did) you are now going to add some parts that otherwise would have to be added at a later day when you decided to make the rig an SSB rig. There are some cap's, a resistor pack, a resistor and finally Q3. I don't want to be preaching but if you plan on at some point using the rig for SSB you may want to add this Rework option
Rework parts for SSB Mic option
that allows you to change out mic's with just changing some  jumpers as well as make the K2 SSB ready. Once the K2 is built sure you can add these parts but it means taking the rig apart and soldering them in.Well now it's time to move on to the next step including the LCD and this is a section of the build were taking your time and checking and double checking are key!

Thursday, April 18, 2013

Control board add on...........

KAF2/KDSP2 rework board in place
The control board has one Rework eliminator  on it and it's for the KAF2 or the KDSP2 Elecraft modul. If this Rework board was not included in the kit build and you wanted to add either the KAF2 or KDSP2 you would have to take the K2 apart  add the SIP connectors J1 and J2 to the control board board. But also remove two resistor (R18 and R19) from the control board. With the Rework kit it's plug and play!  When building the K2 kit Elecraft has done their best to make it a very easy and fun experience. I found it to be a whole different ball game when a board is built, tested and installed to have to remove parts! There is de-soldering wick,
Rework board removed
de-soldering pumps  and also the Hakko 808 desoldering tool (which by the way is well worth the money I have one and it's great). The way I look at it just to much can go wrong when removing parts on a finished board.....why give Murphy the upper hand!

Monday, April 15, 2013

The Control board is complete

Done and ready to go into an anti static bag
The first step of the build is done....the control board! This is a great board to start out on as there is no dreaded toroid to wind, real tight components to solder and at the same time there are some difficult parts in this part of the build to get the confidence scale to rise! In the Elecraft manual you will notice that at the end of each section of a build there is a check out section. In most cases it involves some resistance checks outs. I strongly recommend you do each and every one of these checkouts! You may have done a great job of soldering, getting the right parts in the right place and double checking everything as you went
The test of U6 Pin 29 and 30 as per email
along....BUT.....the checkout will prove all components within the checks fall into spec. Case and point....as I was doing my checkout on page 22 of the manual I found that on U6 pin 29 and 30 were not within the 70-90K my reading was at 95k. So I emailed the reflector and was told to do a check  involving shorting to ground a pin on U5. I was told when this is done I should get within the range and I did, my reading went to 95K to 81K. It's now to move on to the next board and the adventures that await me.

Friday, April 12, 2013

Adding a bend or two in the build


Part to the control board build involves fabricating 2 capacitors on the back of the control board. This is not a real big deal but can become frustrating if you don't take your time. If you come to this step and have been at the build for some time and are feeling tired then leave it for the next day. Capacitor 103 (the red one) is a bit more involved as the bends are tricky as well you have to add some insulation the the leads. First off before adding either cap to the board check and double check the location. It's funny how lots of places on the board look the same. With Cap 103 I was not sure if it was better to add the green insulation to the wire cap leads and then bend the leads into place or to bend the leads then add the insulation.......So I tried both ways and there are good and bad to both!

Bending cap 103 leads first

- I was able to easily bend the leads and lay the cap on the board to see how the fit was going.
- Sharp bends (like those at the cap body) were done without any trouble.
- Adding the green insulation was a treat when it came to the tight bends, I found it got hung up.
- The extra pushing needed to add the green insulation took out some of the critical bends out of the leads. So I had to re-bend the wire leads several times.

Bending cap 103 with green insulation wire on

- It was nice to not have to fish the green insulation on once the cap leads were shaped. 
- This method was a one step process, once the bending was done that was it.
- Real sharp bends were not possible.
- At first I used small needle nose pliers to bend the wire but I found this deformed the green insulation on the wire. Once I switch to small jewellers screwdriver to bend the leads around without using pliers the leads looked much better.

So what method do I recommend using.....put the green wire on the leads and then start the bending using smooth utensils to do the bending. Tools such as jewellers screwdrivers, dental tools or any other smooth object you can come up with to do the job. 

CAUTION...CAUTION....CAUTION.....
When cap 103 is ready to be soldered to the board, with the green insulation  in place and the master piece is good to go......make sure you add the heat from the soldering iron for only VERY SHORT INTERVALS or you will be starting over again as I did!! The insulation will melt very very very easily and expose the conductor to possible shorts. If you do happen to melt the insulation don't leave it have a break and  start over again.

The blue capacitor I found to go real smooth compared to cap 103. No insulation is involved and that is a big bonus. Take your time bending the leads so there is no stress on them when making the connection. 
I also found that adding a downward angle to the leads once they are bent helps the capacitor to lay nice and flat on the board. This is because the leads are in the centre of the capacitor and will sit above the spot where they are to be soldered, a small bend downward at the capacitor "can" will allow the leads and capacitor body to sit nicely.

Sunday, April 7, 2013

A new page has been added

The control board on the K2 project has been done and checks out to be just fine!! I am now going to add over the next little while some of the challenging sections of the control board build, some of the "say what" of the control board build and just plan old...here is how I did it sections. I have added a new page to the blog called "control board" and it goes over some of the tricky parts of that build. I will be adding to this page as time goes on and as I get feed back as well. The page has internal links to pictures on how to bend the transistor legs into a nice tripod configuration. As well as how to get the power transistor to fit on the PC outline with out pulling out your hair in the process. How about soldering grounds to the crystals..well that is there too along with links to pictures. It's now time to move on to the front panel build!!!