/diy/ - Do It Yourself

>>682252
>I don't know if there's any particular handling procedures for tubes like that
not really, just make sure they are cool enough to touch. you might have to wiggle them gently as you pull them out. don't slam them around, it's glass and the inside is delicate bits. there is an alignment key so you can't put them back in wrong and since the schematic shows both as 25D6-GB tubes in identical circuits it won't hurt if you mix them up.

it sounds like cleaning it out and the proper size fuse may be all you need.

>>682213
>people keep mentioning that this sounds like a bad capacitor. is there anything I should be looking for regarding these components?

for your future reference
visually a bad capacitor may show signs of swelling, cracks or discolored areas due to heat damage or it may show no external signs of malfunction at all.

small value capacitors will show a very high resistance when you check them with an ohmmeter. make sure the power is off and device unplugged and be sure to short out the terminals of the capacitor prior to checking it, as capacitors can store a charge for a long time. the exact value the ohmmeter should read depends on a lot of things, if in doubt check another similar cap and compare readings. I would expect the caps in your device to show at least 100 K ohms maybe even much higher.

>>681813
OP, I have a final thought for you.

In situations such as yours I have advised clients to increase the amperage rating on the fuse slightly (20%~50%) and continue operation of the device under close observation. If the fuse does not blow... problem solved. If the device operates for a while and then the fuse does blow, increase the size again. This will cause the failure of the intermittent part eventually and you will have no problem figuring out which component was giving you the problem all along.
>the weakest link in the chain
This is not the best solution but it is a workable one.

Intermittent defects are the bane of the troubleshooter.

>>682037
that's all external, the damage is to the finish of the weatherproof box and is most likely unrelated to any interior situation.

it's normal and if it were dangerous the meter reader would have reported it.

>>682148
forgot pic

>>682069
umm... anon I circled C5 & C6 in white. the reason I think they may be the culprit is the only components on the input side of T2 (the major power consumer) are T1 a transformer for the tube filaments which almost never go bad and the fan motor and the primary winding of T2 and the filter caps C5 & C6. parts on the secondary side of T2 would have a difficult time blowing the fuse in comparison with the parts I previously mentioned. a dead short on the secondary side of T2 might not blow a fuse, but a short on the primary side sure will. since OPs problem is intermittent, a leaky capacitor fits the bill. most other high current failures cascade into a full blown short, things that don't are motors and capacitors. the windings in a transformer almost always cascade into a full blown short or open and do not ordinarily display intermittent high current as a mode of failure.

>pic shows 2 fuses

>>681813
I have a couple of questions.
a. I see two fuses in this pic>>681814
but only one on the schematic. do both fuses blow or only one?

b. is there actually a spin dry motor?

if it's not the fan motor or spin dry motor wearing out my next guess would be either C5 or C6 is leaky, you can check with an ohmmeter, read up on how.

be careful, do not touch the bare wires while the unit is plugged in. the capacitors can hold a charge long after the unit is unplugged so always use a screwdriver or something to short out the terminals on any capacitor you might touch or want to measure.

>>681837
if you've been into welding for years you've got the basics of handling hot parts.
in welding you melt all the parts base metal and filler, in soldering / brazing you only melt the filler material.
electrical soldering is the easiest, the soldering irons are the right temp, and the solder has flux built in. as long as the parts to be joined are relatively free of oxidation and foreign material once the parts to be joined reach the right temp the solder will flow and wet all surfaces. if you have done it right with enough heat the results will have a shiny apperance. too little heat, or removing the heat too quickly will result in a grainy appearance and a weak connection that can fracture easily, commonly called a cold joint

doing things like plumbing / guttering / roofing or jewelry is a bit different because you are trying to fill an area between two surfaces. getting proper surface prep and fluxing along with even heat allows the solder (or braze) flow properly and wick into place.

>>681838
root cause?
oxidation of one or both mating parts before initial install or lack of physical pressure on contact areas due to warped / bent parts
I'm talking about the part of the breaker that connects with the buss in the panel.

high humidity situations can cause these problems but you would find it in all the breakers.
this was most likely a bad contact situation from the get go.

the problem doesn't show up for years sometimes until sufficient warpage / oxidation occurs and arcing begins (the flickering)

this anon has part of it>>681640
the whole picture includes small spot arc welds that conduct for a while then burn out like a fuse, causing another arc spot weld to form and so on.
the whole thing was an electrical fire waiting to happen.

good thing you caught it OP, any time the lights flicker or the distribution panel smells funny or buzzes or is more than slightly warm to the touch you have a problem.

>>681617
If the electrician was competent he checked to make sure the new breaker made good contact. You can check by measuring the temperature of the breaker under max load. the breaker should not be hot to the touch, normal operation is only slightly above ambient, any warmth above that indicates a problem.

DO NOT TOUCH THE WIRES OR TERMINALS
just feeling the bakelite case on the front is enough.

the professionals use infrared thermometers or photographs to spot these problems.

>>681617
>What caused the breaker to look like that any ideas?

long term heat damage to the bakelite case causes the crumbled appearance.
the screw terminal matching the damaged connector also shows more tarnish than it's mate most likely from heat.

Most likely cause was poor electrical connection between the buss and the breaker causing heat. I would expect the male part of that connection (buss in the breaker box) to show discoloration due to heat, and possible obvious fused spots due to intermittent arcing.

>pic related, small arrows show possible arc spots

>>679910
or power supply goes pfffft and voltage drops to zero

>>677651

>>674312
>I want to take the part I have in hand,

since it seems by reading this thread you are trying to replicate a part for a restoration, you might want to re-think the scanning part. I would suggest a more direct method of mold making. It would all depend on the level of detail your scan can reproduce and the level of detail you wish to replicate in the part.

a good replica should have the original casting marks and makers mark

>>674739
the base of the transistor needs to be biased correctly. the raspberry gpio may not have enough current to fully switch the transistor on when the pin goes high

>>674082
not the best of pics anon, but if it is as you describe it, it is a basement or crawlspace foundation wall.

re-route your trench

>>674115
>why would you not wrap a conductor around yourself?
I can think of reasons on both sides, it would depend on the environment you were working in.

>I've worn grounded electrostatic protective suits where everything but my face was a conductive layer.

>grandfather had a huge scar on wrist where watchband caught between positive terminal on car battery and chassis and melted.

>>673511
from what little I know it sounds like JT65 might be something within reach.

I'm looking into the whole thing right now myself, and will try for license in next few weeks.

if you have a computer you are half way there.
I'd get one of those USB tuners for the receiver for about $20 (I found one on ebay buy it now 13.49 free shipping)
see for how to modify it and set it up to use the free software http://www.rtl-sdr.com/

and since JT65 uses the sound card for the mod / demod and uses 10~40 Watts max a simple linear amplifier circuit shouldn't be too hard to conjure up.

there are plenty of antenna web sites to help with design and construction hints for long wire type antennas which are pretty cheap, or build your own beam antenna if one of the omni rhombus designs won't do.

good luck

>>673341
>Teh fuck are you talking about
straight AmplitudeModulation

>>673250
well, that's a start.
what other resources do you have?
I'm not familiar with the license levels, does a general allow you to build your own transmit device?
do you have space for HF antenna?

>>672786
a motion detector with some sound effects hidden in a public park?

the meow of a cat at a neighbors house that has inside dogs?

>I don't know officer, every time I jog along this path I hear the strangest noises, kinda creeps me out

>>672903
double D rings
>pic related
I'd get some that weren't "D" shaped but rectangular.

If you get silver plated wire you won't have the tarnishing problem

and this anon >>673043
has a VERY valid point that you very much need to understand

>>672875
>And people agree to this?
refineries and oil/gas rigs & pipelines pay good money for that very reason anon

>>672803
>If I get that circuit it starts broadcasting at the resonance frequency if I were to attach a wire at the output?
simple answer... YES

in real life you need to match the output of your device to a transmission line (coax) and that connects to the antenna. the impedance needs to match at each connection for good efficiency. That being said a poor connection and a poor antenna will still radiate something.

here is a website you might like
http://www.antenna-theory.com/

>>672703
>After a bit of reading on the internet it seems that a changing current induces radiowaves on a conductor.

a bit of reading probably won't quite cover it anon. to start with it's poor form to say "radiowaves on a conductor", when it's in a conductor it is considered an alternating current, radio waves exist outside of what is normally considered a conductor (air, the vacuum of space etc...)

>How do I go from here?
resonance is the start
just because a conductor carries an alternating current does not mean it will radiate off into space as a radio wave. several things must occur. Low frequencies (50/60 Hz) are more difficult to get to radiate efficiently and high frequencies (GHz microwaves) are hard to stop from radiating away into space.
And once you have created a source for the particular frequency you want to use and are able to get it to give off radio waves you still have the question of how you have modulated (encoded) your information onto the wave, (the carrier).
Your choice of FM (frequency modulation) is not the simplest. FM means that the changes in the input signal (usually voice or music) make changes in the carrier frequency, small changes in the signal make small changes in the carrier frequency and large changes in signal make large changes in the carrier frequency. Now as you can imagine these changes have to be limited at the large change end to keep the radio waves in the correct channel / band, so that your signal does not interfere or overlap with other stations broadcasts.

there are many fine sources of information on the interwebz, I would suggest ARRL as a starting place