Hi everyone I reached the first resistance test and the reading on the 5v line is 695 ohm using 2 meters fluke 87 and my PC interface radio shack meter. Q1 Q7...
12411
scott schoech
scottschoech
Jul 1, 2007 9:29 pm
Jeff, Sounds like I'm not the only one who has troubles when building. Scott Jeffrey Peters <K9JP@...> wrote: Tim, Make sure you have scraped the...
12412
R. R. Robson
wb5rvz
Jul 1, 2007 10:02 pm
I have finished adding resistors and diodes to the board and have not yet layed in any transistors or inductors. I did the measurements and got: - for the 12V...
12413
Tony Parks
kb9yig
Jul 1, 2007 10:26 pm
Hi Steve, Your resistance reading is enough off that I think there may be a resistor or two not installed properly. Please look carefully at the mounting...
12414
Tony Parks
kb9yig
Jul 1, 2007 10:30 pm
Hi Robby, The 993 ohms sounds a bit high but may come down when the transistors are added to the board. I will check but I am pretty sure your missing TO18...
12415
Bill Dumke
billspiro1
Jul 1, 2007 10:36 pm
David, I assume this filter board will only work in receive. Are you planning to make another one for transmit? Bill wa9pwr...
12416
Steven Gorkowski
steve_kb4mxo
Jul 1, 2007 11:18 pm
Hi Tony After looking at the resistors R15 and R16 I put them in the wrong direction. Removing them now and installing them properly. Thanks Steve KB4MXO ... ...
12417
brainerd@...
brainerdd
Jul 1, 2007 11:28 pm
... Bill, Correct, unless it's QRPp! The smd coils will take only a few hundred mA and the switches are only rated at 3.3V. I have a design I did a while ago...
12418
Philip Hahn
everphilski
Jul 2, 2007 12:18 am
Yup, R15 and R16 got me too the first time around. Of course the markings are right there on the board, for some reason the parts just wanted to go in the...
12419
Steven Gorkowski
steve_kb4mxo
Jul 2, 2007 12:53 am
Hi Phil I figured someone ran into this problem and had the fix. I now have the 814 ohm reading on the 5v bus. Its a blast to build this board. Steve Kb4mxo ...
12420
D. Mynatt
davemynatt
Jul 2, 2007 1:09 am
Hi- Are you still open to assemble a kit? I have a 10.7 Softrock I need help with, and I can have Tony ship to you if you're still available. I have no hope...
12421
Tim Gorman
tg6124
Jul 2, 2007 1:25 am
The connections are good. The instructions are just the teeniest bit vague. Should one of the ends of the bifilar pair be soldered together and used as the...
12422
Tim Gorman
tg6124
Jul 2, 2007 1:49 am
On Sunday 01 July 2007 16:29, scott schoech wrote: Oh golly, you aren't alone in having to try multiple times to get things right. I've been doing this for...
12423
Kees & Sandy
keestheham
Jul 2, 2007 1:58 am
As you approach the specified OpAmp Gain Bandwidth, how does the OpAmp react ? Rfb/Rg no longer specifies the OpAmp gain (less) ? The OpAmp becomes less...
12424
Bill Dumke
billspiro1
Jul 2, 2007 2:12 am
Kees, The gain bandwidth product is a constant for any opamp. You have maximum BW at Unity Gain and Maximum Gain at a very Narrow Bandwidth. Stability is...
12425
Milt Cram
w8nue
Jul 2, 2007 2:18 am
... Kees, The OpAmp Gain Bandwidth is the frequency at which the amplifier gain drops to unity. No combination of Rfb/Rg resistors can make the gain any...
12426
Lyle Koehler, K0LR
k0lr
Jul 2, 2007 2:24 am
... Only one wire goes through each of the six circuit board holes. Make sure that you have marked the primary winding with spray paint or something like a...
12427
Kees & Sandy
keestheham
Jul 2, 2007 2:52 am
Thanks for the response Bill. I was just wondering what happens if you exceed the GBW ....say you have a frequency range into the OpAmp and a gain which when...
12428
Kees & Sandy
keestheham
Jul 2, 2007 3:04 am
I should say "try to exceed" the GBW......... -- "Kees & Sandy" <windy10605@...> wrote: Thanks for the response Bill. I was just wondering what happens if...
12429
Kees & Sandy
keestheham
Jul 2, 2007 3:05 am
Thanks for the response, Milt. I think that's basically what I was saying...... The GBW is the max frequency for a gain of 1, you can also max out at that...
12430
Lonnie Ahlfinger
lonnw6wq
Jul 2, 2007 3:13 am
Attached is a photo of a Softrock Light transformer I made, I used a little clear gelled or thickened Acrylic Cement to hold the wires in place, it drys within...
12431
Philip Hahn
everphilski
Jul 2, 2007 3:20 am
Yup, me too. Mine is complete however I have no phone jack plugs :/ Further testing and use will have to wait until tomorrow ... awaiting anxiously, Phil,...
12432
Tony Langdon
proton69au
Jul 2, 2007 4:05 am
... You can't exceed the GBW, it's a physical limitation of the op amp being considered. In fact, as you approach the unity gain frequency, the op amp is no...
12433
Tony Langdon
proton69au
Jul 2, 2007 4:08 am
... You'll get less gain and/or bandwidth than you hoped for, for starters. If there are any non linearities in the op amp at high frequencies, these will...
12434
Tony Langdon
proton69au
Jul 2, 2007 4:19 am
... The frequency response of the amplifier is affected by the gain. As you increase the gain (by changing the feedback resistors), you lower the frequency of...
12435
Alex, VE3NEA
alshovk
Jul 2, 2007 4:21 am
Rocky 3.31 is available at http://www.dxatlas.com/rocky/RockySetup.zip .This is a maintenance release (no new features) that is supposed to fix the errors ...
12436
Roderick Wall
radioaustral...
Jul 2, 2007 4:33 am
Hi Tim, When I wound my coils, I made the leads for the bifilar windings shorter and left the leads long for the other single winding. Easy, the ones twisted...
12437
Roderick Wall
radioaustral...
Jul 2, 2007 8:14 am
Hi Alex, I've just downloaded and installed Rocky 3.31, so far is has been working ok, I only have one soundcard installed so I can only use Rocky in receive...
12438
Tony Parks
kb9yig
Jul 2, 2007 8:33 am
Hi Roderick, A low cost soundcard, that I would think would be available in stores in Australia, could be selected in Rocky for the speaker audio output. That...
12439
Andrew O. Ojwang
ft_5
Jul 2, 2007 9:12 am
I just looked at your BPF filter designs, good idea. I am putting a tunable BPF filter together, but it has too many switches, but never considered using CMOS...
