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Re: lockdown boredom

Posted: Thu Apr 30, 2020 1:31 pm
by Santiago
shame, will have to roll without then

Re: lockdown boredom

Posted: Fri May 01, 2020 9:19 pm
by Santiago
checked mine for power today got about 6/7 watts, listened through some headphones to check it was locked and there is a high pitched terrible hum, could it be the psu?

Re: RE: Re: lockdown boredom

Posted: Fri May 01, 2020 9:29 pm
by Electronically
Santiago wrote:checked mine for power today got about 6/7 watts, listened through some headphones to check it was locked and there is a high pitched terrible hum, could it be the psu?
High pitch normally means your swr is high. Or earth problem. Depends what psu you have going through it.

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Re: lockdown boredom

Posted: Fri May 01, 2020 9:34 pm
by Santiago
it's going through meter into a dummy load, might be psu? it's a small one 15v rated 1.5amps

Re: RE: Re: lockdown boredom

Posted: Fri May 01, 2020 9:39 pm
by Electronically
Santiago wrote:it's going through meter into a dummy load, might be psu? it's a small one 15v rated 1.5amps
Sounds like the psu. Double check the earth inside psu is connected could off fell off if dropped etc. Only way to know is try another power supply if that stops it then must be. Or maybe your to near equpimenet to cause a buzz.

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Re: RE: Re: RE: Re: lockdown boredom

Posted: Fri May 01, 2020 9:41 pm
by Electronically
Electronically wrote:
Santiago wrote:it's going through meter into a dummy load, might be psu? it's a small one 15v rated 1.5amps
Sounds like the psu. Double check the earth inside psu is connected could off fell off if dropped etc. Only way to know is try another power supply if that stops it then must be. Or maybe your to near equpimenet to cause a buzz.

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Does it hum with swr meter disconnected if not then there's your problem.

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Re: RE: Re: RE: Re: RE: Re: lockdown boredom

Posted: Fri May 01, 2020 9:45 pm
by Electronically
Electronically wrote:
Electronically wrote:
Santiago wrote:it's going through meter into a dummy load, might be psu? it's a small one 15v rated 1.5amps
Sounds like the psu. Double check the earth inside psu is connected could off fell off if dropped etc. Only way to know is try another power supply if that stops it then must be. Or maybe your to near equpimenet to cause a buzz.

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Does it hum with swr meter disconnected if not then there's your problem.

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Or either set it back to 13.8v just the your board might no like 15v. So that might lower the buzz.

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Re: lockdown boredom

Posted: Fri May 01, 2020 9:53 pm
by Santiago
board says 15v on the input, checked psu with meter, its giving 15v, ill try without swr meter plugged in

Re: RE: Re: lockdown boredom

Posted: Fri May 01, 2020 10:01 pm
by Electronically
Santiago wrote:board says 15v on the input, checked psu with meter, its giving 15v, ill try without swr meter plugged in
OK try that

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Re: RE: Re: RE: Re: lockdown boredom

Posted: Fri May 01, 2020 10:15 pm
by Electronically
Electronically wrote:
Santiago wrote:board says 15v on the input, checked psu with meter, its giving 15v, ill try without swr meter plugged in
OK try that

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If that doesn't work try decreasing a watt or two

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Re: lockdown boredom

Posted: Fri May 01, 2020 10:41 pm
by mikroman
If you are using smps power supply it is very likely that it is poorly filtered.

Re: lockdown boredom

Posted: Sat May 02, 2020 9:26 am
by Santiago
it's not a switch mode, prob worse lol

Re: lockdown boredom

Posted: Sat May 02, 2020 9:41 am
by teckniqs
That is indeed a switching mode supply, what makes you think it isn't?

...I tried running a band one link box from one a while ago and there was a high pitched "whining" sound coming over the audio, as soon as I changed it to a standard transformer with bridge rec and smoothing cap it was completely gone.
Same thing happened when I tried to run a microwave midpoint from a laptop charger.

Re: lockdown boredom

Posted: Sat May 02, 2020 10:04 am
by Phoenix
Get a proper PSU
That is a horrible switch mode thing
Transformer rectifier and smoothing cap

Re: lockdown boredom

Posted: Sat May 02, 2020 10:48 am
by Santiago
like u said its prob worse, I was correct.

i literally dug it out to test the board, was going to run it off a car battery if all was well, which it seems to be mi us the psu

Re: lockdown boredom

Posted: Sat May 02, 2020 12:36 pm
by teckniqs
Car battery will be fine, like the cleanest DC supply that anybody can offer.

....Just remember to be careful not to let it drain below 11v. :tup

Re: lockdown boredom

Posted: Sat May 02, 2020 12:51 pm
by Santiago
I'm going to add that 12v voltage cut off board off flea bay that pranker recommended.

I have a dipole I can use, but was thinking making something with a little gain, depends how much free time I have over over jyn e next few weeks

Re: lockdown boredom

Posted: Sun May 03, 2020 2:54 am
by Albert H
If you're heading for the trees, you want to get the aerial above the foliage if you can. I used to use wire J-poles inside white plastic plumbing pipe. Paint the pipe pale grey or blue with acrylic paint, and it's practically invisible from the ground!

Re: lockdown boredom

Posted: Sun May 03, 2020 9:02 am
by Santiago
Albert I'm thinking flower pot antenna, not not sure if I'm calculating right, 2 quarter wavelengths of 81.3cm and 13 turn choke on a 32mm pipe is 87.6?

Re: lockdown boredom

Posted: Sun May 03, 2020 7:27 pm
by surefm
Finally got this working ok, Audio in just using mono and sounding ok with little hum, just running it at 1 watt but it did go up to 8 watts full power,
going to use it just for a driver board is my plan.