PA100-D

[VK4GRM]

Hi
I am new to the forum so please let me know if I don't ask the questions appropriately.

I have just completed the PA PCB for the PA100-D and was wondering where the nylon washer identified in pack 4/7 of the JUMA PA100- RF amp. Rev.C is supposed to go. I have placed it on Q3 but I could not find any indication of where it needs to go in the photographs?
So far I am very happy with the kit as it all appears to go together well and looks great.


Next question is in relation to the Main Board. Are there any detailed pictures of each step in the construction process like there were for the PA board?
It seems to be reasonably straight forward so maybe more detail is not required? I would like to review any details before I commence construction if there is some detail available where I have not looked.


Thanks for your help


Greg
VK4GRM

[WA4MZS]

Hi Greg,
You've got it right, nylon washer goes with Q3.

Main board . . . nope . . . no step by step published instructions that I know of. If you just follow the order of the components on the parts list (the complete one on the Juma website) it'll work out well. Mainly smallest components first amd working up to the larger ones. Same for the Control board. However I did have someone else install the 80-pin µcontroller. It was a bit much for these 75 year old eyes and shakey hands! All the other stuff went really well. And it was my 'first shot' at SMD components.

It's a very nice little amp and I think you'll really like it. After assembly, mine met or exceeded all specifications. Using it with a Yaesu FT-817nd, but thinking real hard about the Juma TRX2A (as soon as it's available again).

73
Ed.
WA4MZS (for 55 years)
CWO3 USCG (Ret.)

[VK4GRM]

Thanks Ed for the reply,

I figured that that was the logical place to put it so it looks like I was correct.
I am in the process of capturing my build with a "How to" document with a combination of the Juma photographs and my own so I will include some pics of the Main Board at each of the stages. It may help someone else down stream.


I built a Genesis G59 (SDR kit) a few years ago and plan to marry it up with the JUMA 100W PA as I mainly work FT8 mode and my 5 to 10W is a bit limiting. I also need to finish my auto tuning Magnetic Loop antenna to go with both of them.


Looking forward to completing the kit. Only problem is finding the time


73

Greg

VK4GRM

[WA4MZS]

Greg,

Would like to know a bit more about your autotune magnetic loop antenna. Contact me directly. My e-mail address is on qrz.com.

Thanks!

Ed.

WA4MZS

[VK4GRM]

Hi

Another question. I have worked my way through to the Digital board and have a question about the PIC microprocessor that is fitted. The chip has two dots on it as you can see in the attached photo.

Which is the correct dot to identify the reference corner?

One of the dots has a double ring on it which I am assuming is the correct location of the reference corner as shown on the attached photo.

Note I have not soldered the chip onto the board yet.

Ed I will send a separate email re the magnetic loop antenna in the next few days. A bit late to send tonight

Regards

Greg
VK4GRM

[WA4MZS]

Smaller dot is the reference mark. N3ZV (Whitney) installed the µ-processor for me in my PA100, so we'll give him credit for that. I'll see if I can attach a picture of it. To me, it's a bit confusing . . . but . . . ??!! Something I did notice on the Juma web site was one of the pictures of the µ-proc. showed it with what appeared to be a white adhesive label with a single black dot on one corner attached to the top of the chip. Oops! it said the file was too big. Anyhow . . . small dot is the ref.

Ed.
WA4MZS

[VK4GRM]

Thanks Ed. I have now installed the PIC.

Now to install the LCD and other hardware on the board

[VK4GRM]

Hi

I have run into a problem. I have smoked the track on the main board from J7 Pin 6 on the bottom side of the board. This is the +14V line. I had it all wired up and powered up and smoke appeared. Shut down quickly of course. Took me a while to find but the track is definitely damaged I can put a link across it to fix, but I suspect that is not the problem.

I started checking each of the boards for shorts, the RF board is 15MOhms between +14V and Ground.
The Digital board is 2MOhms between Pin 16 (+14Vdc) and pin 12 (GND) on J3

Also I find nothing happens when I apply power to the Digital Control Board. Not sure if these are related at this stage.
How much current should be drawn by the digital board?
I have a small current limited power supply which is tripping at over 1 amp.

There are no obvious signs of damage to any components other than the track on the main board.

Any suggestions would be welcomed?


Regards

Greg

VK4GRM