No more thru-hole PCBs

[Carl-NC]

I am, once again, out of thru-hole PCBs. Please do not order any, because I will not be able to fill the order. I have no plans to order any more. I do still have SMT boards available.

Update: I am now out of SMT boards, meaning I am out of ALL PCBs.

- Carl

[Unregistered]

Carl Noises

I am, once again, out of thru-hole PCBs. Please do not order any, because I will not be able to fill the order. I have no plans to order any more. I do still have SMT boards available.

- Carl

Hi Carl

We are detecting few microvolts , the thermal noise produced by 100K resistor is 45uVolts, which is fixed even for a MetalFilm, and other noises like contactnoise and shotnoise adds and comes to about more than 100uV, and if u use a high feed back like 1Meg at 1st stage we get noise amplification rather than signal amplification....can u comment without ur integrator coming into picture....

regards

[Unregistered]

Hi Carl

I am, once again, out of thru-hole PCBs. Please do not order any, because I will not be able to fill the order. I have no plans to order any more. I do still have SMT boards available.

- Carl

Hi carl can we use low values, a 10K resistor at feed back of Ne5534A and 100ohm from -ve input to ground for a noninverting amp (to get a gain of 10k/100ohm) instead of 1Meg and 1K (@-ve input)

[Gimp]

Carl, since you have not said you are out of surface mount boards, I would like to order one. I sent a PM, but it looks like you havn't seen it.

Thanks.

[KingJL]

Carl, since you have not said you are out of surface mount boards, I would like to order one. I sent a PM, but it looks like you havn't seen it.

Thanks.

I haven't seen a post from Carl since last week. I sent him an email on Monday, but his host mail server bounced it. It's like he walked off the edge of the earth. Oh, that was Marco Polo!

[Gimp]

OK, thanks for the heads up.

[amtech2005]

No more thru-hole PCBs

I thought I read last week on this forum that he was on the road traveling? Anyway , There is enough information on this forum to make the latest Hammerhead PCB circuit board . Surface mount or Through-Hole. I like the through-hole !!!!!! Cause then I do not need Glasses to see what I am doing !! Take Care , Eugene

[Carl-NC]

Hi all,

Yes, I have been traveling, and yes I've been to the edge of the Earth & back! Gimp, I will try to get your PCB mailed out tomorrow, as I am heading back on the road for another week. Sorry for the slow reply.

- Carl

[Gimp]

Thanks Carl, I appreciate it.

Be careful on the road.

[Gimp]

Got the board Friday. Thanks a bunch.

Open question on parts for the board, where do you get the .47uF film caps? The only ones I find from Digi-key, Newark, etc are much too large (Bigger than 1812 which would be a squeeze) to fit the board.

I don't want to use ceramic MLCs for timing circuits and certainly not for the integrator.

[Carl-NC]

I'm using MLC caps everywhere. I doubt you will find SMT film caps that will fit.

[Unregistered]

question

I am, once again, out of thru-hole PCBs. Please do not order any, because I will not be able to fill the order. I have no plans to order any more. I do still have SMT boards available.

- Carl

There is a design issue in one version of HH, the Ne5534 opamp balance circuit should not be given at the inputs (as in some designs) use the balance circuitry, as this is for amplifying low level signals, noise from the balance resistors will add up.

One more question whats the advantage of inverting opamp, also its high noisy feedback resistor of 1Meg feeds into the input.

One more question, 555Ic's do not jump to 0V while going low (as per data sheets the 555IC's low level will be at 1.2 Volts ie above reference at 10V supply) and we are switching off the Fet with 555, but the low level is 1.2 volt not 0V, here the voltages are -10and 0V, Will the fet switch off completely due to -1.2V.

Another question the Fet Drain in Twin Loop Treasure seeker is connetced to 0V thru the resistor R17 and cap C13 high pass filter, we have to take this as drain connected to 0V, and the gate driven from the 555 -1.2V at off condition will the fet switch off completely.

[Carl-NC]

See elsewhere (Tech forum, I think) my noise analysis thread. Thermal noise gets averaged by the integrator so is not such a big issue. Bipolar 555's do not go to zero; I believe CMOS versions do, which is what I use.

- Carl

[jantnadal]

carl

hello carl wanted to ask you this is the last of the final versión heammer head (hammer), the system uses VLF and IP is the same DEEPERS MF or 2x1 system respond by citing

[Carl-NC]

I'm not doing any more with HH1, but other projects are in the works (HH2, maybe HH3). These are PI, not VLF. The Deepers MF is also PI, it just has a variable pulse rate (as does HH1).

- Carl