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Re: SWR Sweeper PC Board version 1.0

PostPosted: Tue Jul 29, 2014 8:05 pm
by VK4KL
Thanks Alan I will take 1 board will transfer funds later today

Adrian

Re: SWR Sweeper PC Board version 1.0

PostPosted: Wed Jul 30, 2014 12:19 am
by VK4KL
$$$ deposited for sweeper board

Adrian

Re: SWR Sweeper PC Board version 1.0

PostPosted: Wed Jul 30, 2014 2:51 am
by w6akb
Order and funds received.

Re: SWR Sweeper PC Board version 1.0

PostPosted: Wed Jul 30, 2014 5:35 am
by VK4KL
Now wait for barrage of questions :lol:

Adrian

Re: SWR Sweeper PC Board version 1.0

PostPosted: Thu Aug 21, 2014 5:42 am
by VK4KL
Board arrived today and it looks good. Will start on the project tonight

Adrian

Re: SWR Sweeper PC Board version 1.0

PostPosted: Tue Aug 26, 2014 2:52 am
by K0PER
I've had my sweeper board and DDS-60 for some time now, and have them assembled. Unfortunately, the board seems to have no love for me. The display lights up, shows the readout headings (FcMHz, etc), but nothing else. Ever. If I switch the program to run the 7.15MHz SWR test, it reads 60, 60, (both values vary between 58 and 60), and 9.9:1. If I change the SWR test program to 28.400, I get the exact same results. The fan dipole tunes to below 1.5:1 across the entire 10m band, as well as 40, 20, 15, 12, and a few others. I obviously have something Not Right, but I'm not sure what or where. If I put my (very cheap) o-scope on the output, I get a very dirty, poorly formed signal, which I think isn't actual signal, but is noise.
The only thing I can think of are the caps I used. I used what I had on hand, which were properly rated ceramic disc caps. Should these be electrolytics? Poly? Should I look elsewhere?

Re: SWR Sweeper PC Board version 1.0

PostPosted: Tue Aug 26, 2014 4:03 am
by K0PER
On further investigation, the reference oscillator (U4) on the DDS-60 isn't putting anything out. This could be a problem. I'll have to keep digging, but it's getting late tonight.

Re: SWR Sweeper PC Board version 1.0

PostPosted: Tue Aug 26, 2014 4:22 am
by w6akb
Good find on the ref osc. Hopefully it is something simple, I'd put it under the microscope and inspect for shorts, check the regulator for proper output voltage at the osc, etc.

Re: SWR Sweeper PC Board version 1.0

PostPosted: Tue Aug 26, 2014 11:01 pm
by K0PER
Poking around at the board and consulting the DDS-60 docs reveals the problem: Insufficient supply voltage. I'm feeding my arduino (currently) via USB. This puts +5VDC on the arduino's Vin pin, which is where the DDS-60 draws its power from. The DDS-60 specifies 8-12v input. My Arduino Duemilanove can take up to 12v on the external input. Changing to a 10v supply adds considerable heat, but seems to resolve the problem. I won't know for certain until I get home and get it on a proper antenna, but this seems to have fixed it.

Re: SWR Sweeper PC Board version 1.0

PostPosted: Wed Aug 27, 2014 12:27 am
by K0PER
I'm still having a problem, even with the new power supply. In either SWR Search or Smart Search modes, it either never displays anything but the header, or flashes a result and then quickly clears it from the display, leaving only the header. For example, I narrowed the search, to 26-30MHz, as this is where the antenna I have is set (known good, a CB antenna in this case, with a resonant point right around 27MHz). When I run SWR Search, it displays 26.03-27.something, but it flashes and clears so fast that I can't catch it all. On Smart Search, it will sometimes flash a frequency in the 26MHz range, but again, it's too fast to catch. It will do this only once, and then revert to just the header. Also, sometimes when booting up, it will go into the selected mode, but not clear the display first, so the bottom line still has "by Alan B W6AKB" displayed. I don't know whether this is a problem specific to my arduino, or a bug in the software.