| Author |
Message |
    
Al_lafon
Intermediate Member
Username: Al_lafon
Post Number: 211
Registered: 3-2005
| | Posted on Thursday, May 11, 2006 - 11:22 am: | 
|
Hello saw a mod for class AB for this has someone
got a photo of this un-grounding of input transformer so we under stand what end to add
parts |
Al_lafon
Intermediate Member
Username: Al_lafon
Post Number: 212
Registered: 3-2005
| | Posted on Sunday, May 14, 2006 - 11:38 am: |
|
Guess no one wants to talk to me about yhis mod! |
Kid_vicious
Senior Member
Username: Kid_vicious
Post Number: 1587
Registered: 9-2004
| | Posted on Sunday, May 14, 2006 - 5:54 pm: |
|
hey al, im still with ya!
i am looking at the innards of my 300p right now, as i am going to be modding it as soon as i get the variable caps.
if you want to see what im doing, we are discussing it in the modifications section under amplifiers in the thread titled "amp mods 101".
not sure if im going to do the AB1 mod, as right now im just going to increase the SSB delay time.
looing at the input transformer, the end closest to the switches is grounded. it a big foil sheild and you'll have to dremel a "moat" around the spot where the brass tubes are soldered to the sheild so that they are isolated from PC ground.
then you solder a 100ohm 10 watt resistor from the red power wire to the anode of the rectifier diode, and the cathode of the diode to ground.
then solder the choke to the resistor/anode junction, and the other end of the choke goes to the spot with the brass tubes that you just isolated from ground.
its all about the input side of this transformer which is the side closest to the switches.
good luck,
matt |
Georgeodjungle
Intermediate Member
Username: Georgeodjungle
Post Number: 107
Registered: 1-2006
| | Posted on Sunday, May 21, 2006 - 1:14 am: |
|
nice thing about the dremel.
good job... |
Kid_vicious
Senior Member
Username: Kid_vicious
Post Number: 1651
Registered: 9-2004
| | Posted on Sunday, May 21, 2006 - 10:36 pm: |
|
not sure why the post isnt here, but i was incorrect about the end of the transformer to cut!!!
the instructions cam from inspector, and while looking for more mods, i found some details i hadnt seen before.
the cutting is to be done on the OUTPUT side of the input transformer.
to some this may have been obvious but i didnt know.
so before anyone goes a'cutting, i hope they read all the posts!
i wonder what happened to that post?
matt |
Chad
Advanced Member
Username: Chad
Post Number: 838
Registered: 11-2004
| | Posted on Monday, May 22, 2006 - 9:51 pm: |
|
If you look at the Schematic it's really easy to see (unlike in the amp). The CT of the secondary of T2 is grounded. you want to LIFT this and apply approx .7V to keep the transistors turned on. The CT of T1 (the output transformer) primary supplies B+ to the final drive.
I aquired a big dummy load (the para dymanics Can-Tenna) I have an X-force on the bench now I'm rebuilding and I'll get into the KL soon. Gotta recoup some money from the antenna/tower incident  I'd like to keep this hobby self-supporting!
Chad |
Chad
Advanced Member
Username: Chad
Post Number: 840
Registered: 11-2004
| | Posted on Monday, May 22, 2006 - 10:27 pm: |
|
My bad... MFJ "Can tenna" derivitave |
Kid_vicious
Senior Member
Username: Kid_vicious
Post Number: 1666
Registered: 9-2004
| | Posted on Monday, May 22, 2006 - 10:48 pm: |
|
well, my parts were sent out friday, so it shouldnt be too much longer before mine is back in commission.
cant wait for you to get inside yours chad!
i think what al lafon was looking for was some very detailed instructions on how exactly to do the mod.
maybe when you get into yours, we can all do the mod together!
if i was closer id gladly come over and help with the concrete.
have fun,
matt |
Inspector
Intermediate Member
Username: Inspector
Post Number: 160
Registered: 12-2001
| | Posted on Wednesday, May 31, 2006 - 8:06 pm: |
|
Hey, gang...I've not been here in a while (been arguing about the finer points of using NPC-RC mods, at another forum). Hey Kid V. I have been "lurking" on "THE MOD" Group for about a month...good group! I have found, about the KL300p, that the schmatics are labled wrong as for T1 and T2. The small input transformer (T1) is what you mod, and yes, you dremel a cut to isolate the brass-tubes from the ground (this is done at the end toward the switches). Be careful not to cut the black primary wire of the transformer. If you test for continuity, you still may get a reading as there are two 10 ohm resistors going from the pills basses to ground...leave them in-place and ignore your continuity reading and go on. Gota go..be back later! 73s 88s |
Kid_vicious
Senior Member
Username: Kid_vicious
Post Number: 1733
Registered: 9-2004
| | Posted on Wednesday, May 31, 2006 - 10:44 pm: |
|
good to hear from you inspector!!!
now quit arguing and get back to moddin'! J/K
thanks for the clarification, now if we can just put all of your posts together in one spot, we will have something.
is your amp version 3.1 on the RM site?
there is a thread we could use your input on if you're interested; here's a link to make it easy.
http://www.copperelectronics.com/cgi-bin/discus4/show.cgi?tpc=34&post=129900#POST129900
I, and im sure alot of others really appreciate your input.
we need more gurus around here instead of me passing out wild guesses.LOL
take it easy,
matt |
