The chicken stick, how to not to get killed in 1 second flat!
All voltages here, are lethal. (no second chances!)
The HV Chicken stick (English, the High voltage safety discharge probe) (or a Savvy stick? or a brave stick, you can't be brave if not still alive nor can you be a chicken)
Verb? did you Chicken stick it yet? (This magic device avoids all that death inconvenience thing)
Rule 1, Do not work on your rig, drugged, drunk, tired or distracted (turn off TV and CELL), take nap or hire an ELMER.?
Rule 2, Assume all parts inside are at 3000vdc. (assume there are shorted parts inside putting 3000vdc where it does not belong, even the case!
Rule 3, Keep the case grounded to the ham shack ground buss bar at all times. Find a way to get the gear unplugged from A.C power feeds, (wall jacks) and keeping case ground working, mine has rear ground stud that is grounded to my service entrance ground and its ground stake.
Rule 4, Have schematic of your rig, in hand , read it and know where the danger zones are, sure in the PA cages. (Ignorance here, is not bliss)
First off , just let the RF AMP sit for hours, and it will be most time safe, if not , repair the bleeder first , that means find all Highvoltage bleeders in the gear and make sure all are good. (dead cold , gear, no voltages present using and ohm meter and your schematic)
Case in point, SB200;.
Next? if the HV bleeder 15meg ohms is still there AS IT MUST BE !, and working, the voltage drops below 100vdc in 1 to 2 minutes, why not just lit it do its job (wait), or repair that first. Yes watch it do its job using the PANEL meter set to HV , on the SELECTOR KNOB.
If the HV meter is no good , fix that next. (it's a big time safety device, as is that bleeder )
Do not use any RF AMP lacking a working HV meter on the panel and tested and you know it works for sure. (reliable 100%) This AMP by the way, loves to blow up the meter. (so putting faith in 50 year old meters, is risky)(use the double diodes back to back fix on all meters)
You don't need a bleeder in the stick, that can fail too. and kill you , because you trusted the silly stick resistor , that stick resistor can even crack, if dropped, and is redundant to the one you have in the gear now.
Do not fail to test your sticks wiring connections are good and that the resistor inside it is fully good and ready for the job.
Use NO STICK resistor chicken stick, or use the 1000 ohm large wattage resistor that Nichicon asks you to do.
There are 2 stick types, no resistor and yes resistor sticks, the later is to prevent stressing large caps, with a dead short to ground , charged.
Many old hams just jam a screwdriver in (after 5 minutes off or better 1 hour) and hope it don't spark. (this why has merits, in that it can't fail, metal shift of driver to case metal ground)
What do I do?
For the folks that are in a hurry I offer this IDEA:
A NEW (never used) 18" x 1/2" I.D. PCV water pipe sold say at Home Depot, or longer if more scared, you should be, it is LETHAL at 3000vdc. SB200. (SB220 more lethal , on up the power performance scale)
Keep your stick dry.
2-3 feet of stranded wire, Tip to CLIP. (braid wire is #1 first choice, less likely to bend and break or crack) (or as you want)
A crocodile clip at end of that long flexible wire. This type clip works vastly better than the ALLIGATOR type that loves to fall off your ground, use the AMP metal main chassis as your ground. (case is grounded to service buss bar grounds in the shack)
12" of bare solid copper house wiring, stripped, #6 gauge. (Lowe's sells it bare, buy some by the foot there,) the larger the better, for a stiff probe end.
Drill 2 holes in the end of pipe per gauge spec. above, to fit bare wire through it, and make a knot there and out to a pointer you make up., on the end. all from copper wire in 5min work. (it's just a probe, low tech)
Or buy a 6gage to ring lug, clamp and bolt the lug to the pipe then put the 6 gage wire in to the clamp screw and tighten it down. (photos soon)
Then connect your ground clip and wire to that new solid copper wire.. (I just solder it on , it's all copper now, easy to solder it is)
Optionally add a resistor inside the pipe handle wired in SERIES. (see below for best resistors to use) Best is no resistors , IMO, less to fail, is best, best.
The risk here is, CAPS get damaged (from internal flexing shunted HV to ground with 0 ohms in the path) (You decide which matters more?, you or the bloody cap?)
Done , end story, the below is proof of the pudding.
Cap makers rule is:
(the answer from Nichicon (LGN series) is never "exceed ripple current" spec. and that is 1.2amp on mine, but on the spec, stock caps it's 1/3 that and on 50 year old caps, who knows that. Research shows 0.5amps on relic caps)
The best Resistors is the lowest ohms that does not cause excessive stress on the FILTER CAP.'S.
Wire wounds have the best performance here, but ,many are not rated at 2700vdc, at all. The rating are in Joules(watt seconds)
The best answer (to me) is 5000 ohms, at 5watts and the landing time is 1 full second landing on 100volts, never shorter, for 4TC discharge and your safety.
The below is for using this device on systems that do not use bleeders at all inside the equipment.
We need a 3kv rated screw driver here, AND 5000 OHMS NOT 100MEG.! My SB200 has 15meg ohms built in the gear. but takes up to 5minutes to discharge.
A random photo off the net.. not too good so I critique it., do not use Alligator clips use crocodile. The former loves to fall off, is way.(lots of experience there)
The double trouble Aligator here is super bad idea, just lean the driver shaft against the case, for the left photo here. Good luck solding nickel steel shaft, seen right photo.
The above design (to be fair) is generic and for systems that have no bleeder by design. Best wire to use is HV rated wire.(it lasts the longest and is very flexiable)
One guy (WEB) tells that he uses his DMM to bleed it down, so others copy him (internet rumors are endless, and sad to read) and they all blow up their 300 or 600v rated meter, was that nice? or safe? so much for Internet rumors...)
I'm sure glad you were not holding the meter when it blew up. ? (it could also arc over and nail you)
Nichicon spec, 1.15amps surge max ripple Over this number, the Cap's life, is reduced , in the business we call this the "walking wounded."
Last and best, Nichicon says discharge it at 1000 ohms or more, not less , a direct quote off there life time spec, PDF, last page.
I calculate 5000 ohms is best. 5watts , wire wound type, Mouser.com sells them. No high precision needed just around 5k.
Respect the gear and live.!
On my Military gear, a huge 1million watt peak, radar ,etc.(Air Search)
The cabinet knobs that unlock Doors or hatches , the HV , 25kv supplies, had rocker levers inside that grounded all caps at once automatically, (not once did I ever trust those!)
We had this Huge CHICKEN STICK made of 100mm diameter solid Teflon handle 20" long. and 8mm steel rod off end, hooked shape, and strap. We had to handle it in steep ship rolls at 30 degree's... no fun that.
Our MIL spec. chicken stick had no resistors at all, (your life wins over any potential cap damage)
rev 2 ++++ 3-12-2016 ( externalized it , all by self)