Recent Posts

1

Beginners / Re: LM324 Power Supply with variable voltage and current

« Last post by xavier60 on Today at 01:49:38 pm »

Do you mean that I need a separate winding on the transformer or another small transformer for the DVM and tap changer ?

Yes.

2

Test Equipment / Re: Fun With Low Leakage/Bias Current: Femtompere, Electrometer, Keithley 617

« Last post by BD1QMP on Today at 01:47:57 pm »

After put back the original BNC connector, I recorded the offset. Is it normal or not?  thanks

3

Beginners / Re: LM324 Power Supply with variable voltage and current

« Last post by mike_mike on Today at 01:47:07 pm »

Do you mean that I need a separate winding on the transformer or another small transformer for the DVM and tap changer ?

4

Test Equipment / Re: Siglent SSA 3021X... Ooops

« Last post by Joel_l on Today at 01:45:43 pm »

I put things back together enough to turn it on. what I found this morning was slight different that what I found ( thought I found ) last night.

Frequency is OK. I checked several points  and all were good ( Agilent E4432B )

Amplitude seems OK, worst I saw was .6 dBm low. TG trace was not horrible but I don't know what it looked like before. ( pic attached )

Input impedance is still off, the only way I have to gauge this is using one of my transmitters and TX'ing into the SA. Before the over power, I was getting a near perfect SWR, now I get high SWR on all 3 TXs I tried.

When I measure the switches, U1 is different than the others.

I went back and rechecked all the diodes in the path at each stage, all were OK.

I will replace U1 ( maybe all just cause )

Thanks

5

Test Equipment / Re: Hacking the Rigol MSO5000 series oscilloscopes

« Last post by BTO on Today at 01:45:35 pm »

I've updated the other post and there is a DETAILED PDF there............ GO FOR IT !!!
i still haven't made the video but the pdf should take care of everyone i think

6

Beginners / Re: LiPo battery charging problem

« Last post by Gyro on Today at 01:45:34 pm »

No. In fact you should use the manufacturer's utility of some other s/w to terminate the charge at around 80%. Your battery will last far longer then.

7

Test Equipment / Re: Hacking the Rigol MSO5000 - Dr Mefisto Licensing Method

« Last post by BTO on Today at 01:42:28 pm »

UPDATE : The Step by Step Instructional PDF is now available (it's detailed)

Also if possible (Because i'm interested to know) could you please leave comments if this worked for you or if it didn't , i think this will start working for everyone.

8

Repair / Re: LED Strip lights flashing like a bad 90s rave

« Last post by Grytpype on Today at 01:41:49 pm »

Thank you both for the advice. I'll check the LEDs first and carefully pick through the high-voltage side if I'm feeling brave enough.

9

Other Equipment & Products / Re: NO DIY repair for you (festool rotex)

« Last post by kripton2035 on Today at 01:39:47 pm »

so, to finally close this topic ...
I ordered a replacement board from festool, for some 140€ with shipping... and it was not the culprit !!!!!!
the small jst connector at the top of the board goes to a ntc inside the motor cage, that is inside the cage and not removable
(for the record the jst is NOT at a standard pin spaces, at least I did not have the same in stock)
so I cutted the ntc cable, soldered another 100Ω ntc, and voilà... now it's working
it was only some 10cts component that was faulty.

hope this may help someone else.

10

Beginners / LiPo battery charging problem

« Last post by hap2001 on Today at 01:34:07 pm »

Hello.
My laptop only charges to 98% and not higher, but the voltage tops at about 13.18v, which means almost 4.4v for single cell.
Is this something I should worry?
Thanks.