King Cobra PCB

[kt315]

thank you, porkluvr. keep me in touch.

[kt315]

hi Ryszard,

the parcel has been sent. tracking number is RN600422889LT.
thank you for support

[matrix]

hello all
I have some problems with my home made board of KC, Is there a person likes to help me here?
After turning on and battery check tone , immediately a flat prolonged tone appear s ,and stays on.
no effect with changing potentiometers values or switches position, and senses nothing.
Where i make mistake?
My replaced parts are :
1-LM308N with NE5534 as partlist proffered
2-BF245 with K246 (in correct direction g,s,d of course)
voltages on test points when battery is full are :
+8v= 7.4volts -8v= -5.9 volts ( tc7660 may be damaged or voltages are normal? )
Previously thanks every one help and thank you kt315 because of your generosity in presentation free information.
sincerely , M

[kt315]

hello matrix, -8V is low. check SMT resistors on back side were they been soldered rightly.

[Sean_Goddard]

I have thought about getting those same housings and shafts from Keith. How do they look? Is there a faceplate with the housing? Pre-drilled.

Merc

There will be when I get my CNC milling machine up and running over the next few weeks. It's been a long hard slog, with random brearing failures (on a brand new machine too) but after I stripped it completely, and rebuilt using a few better quality parts, all is 100% now.

If you have microsoft Visio, design your panel 1:1 scale on an A3 sized page, email me the file via PM, pay for materials and postage, and I'll mail you the finished panel in anodised (black) engraved and laquered top grade 1.6mm Aluminium.


If you want it pre-drilled and machines with a groove for seals or the like, then you need TWO drawings, front and rear.

ALL dimensions in mm please.

Also bear in mind I will use a NEW TOOL on each piece to ensure best possible finish, to keep your tooling to a minimum or I will charge for this as they do wear out, even on relatively soft Al.

[matrix]

hello matrix, -8V is low. check SMT resistors on back side were they been soldered rightly.

they are in correct place and u2 is powered with them.
there is no part be warmed, all are in normal temperature
also when the circuit is turned off , the resistance between supply points (+8 , -8 , G) is too high .
Can i use 7908 with a -8vdc output instead lmc7660 ? is it correct?
best wishes
M

[kt315]

not, you can not use 7908 instead 7660. but you can connect an outer power supply -8V desoldered 7660 for finding of the trouble. you have to remember that a sound will be absent in this case. disconnect a speaker anotherway it will be burn. then may be the temperature will be abnormal somewhere so it will give a clue to you. maybe.

[matrix]

Hummm
OK.
Thanks in advanced
I will be here again
Best wishes

[eduardo1979]

The King Cobra constant beeps for a few seconds to turn it on. This sound shows the state of charge of the battery. If the sound is short, the battery is low, and if the sound is longer, the battery will have enough charge. My Cobra emits this sound for 2-3 seconds. Greetings.
http://www.youtube.com/watch?v=Gr566gsxSuQ

[matrix]

not, you can not use 7908 instead 7660. but you can connect an outer power supply -8V desoldered 7660 for finding of the trouble. you have to remember that a sound will be absent in this case. disconnect a speaker anotherway it will be burn. then may be the temperature will be abnormal somewhere so it will give a clue to you. maybe.

I did it. After 3 minutes , all parts are cool but u10 (ne5534)was warm about 40 c. and my problem have not solve yet.
Some questions about pcb :
1-why the yellow point is not connected to ground but grounded with a path shown with red color?
2- Is R68 connected to ground with line shown with brown? why not in pink color point ?
best wishes
M

[matrix]

ohhh , there is +8.xx volt on my mpsa13 emitter connected to speaker . Is it right???

[kt315]

I did it. After 3 minutes , all parts are cool but u10 (ne5534)was warm about 40 c. and my problem have not solve yet.
Some questions about pcb :
1-why the yellow point is not connected to ground but grounded with a path shown with red color?
2- Is R68 connected to ground with line shown with brown? why not in pink color point ?
best wishes
M

you can learn the layout but you waste only a time. yes, you are right. my target was to make full copy and layout is not maybe optimal. I have wrote about that. either I will make mine trassing from full zero or I will make only the copy. the copy is fast easy way, it does not load you much. my way was asiatics chinese style copy with additional some mods, so you even can use photos of original board and do not mistakes. all were been clearly mate and seen.
1. easy
2. fast
3. optimal

another way I would got only still an one clone of TGSL I did not want to make of.

have a nice day

[kt315]

ohhh , there is +8.xx volt on my mpsa13 emitter connected to speaker . Is it right???

not, there has not to be DC voltage. only AC. while you hear a sound... may be you do not notice that voltage on the emitter is AC.

[matrix]

I knew KC by your great troubles and in my opinion now this is your product . what i see is a man supports and supports, but i cant support him! in fact i do nothing for him
yeah, seems i have to change my pcb board to a new faultless one, but who can provide it ? unfortunately i am living in embargo , in my country , Iran , even the circuit parts are not available at all, and impossible transfer money to purchase a thing from other country.
I know this is my problem, so let me die in governments sensuality .
sincerely
M

[kt315]

in my opinion you try to find a mistake in the layout while the mistake is at your hand made board. I write again - there are not mistakes in first PCBs batch and not in second PCB's batch, because the board is due full precise copy of the original one, detail-in-detail, line-in-line, point-to-point, I use special utils of P-CAD to find errors/violations on every step. do not waste a time on the pics and find your problem. may be resistors' value or short circuit somewhere, I can only guess.