Copy that. I have heard that you can double the output if you leave out the 68pf cap out. Is that right?funbiz99 said:
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mosfets
- Thread starter bushwacker
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Xy3lon4 said:Copy that. I have heard that you can double the output if you leave out the 68pf cap out. Is that right?funbiz99 said:Put a 4.7k 1/2 watt resistor on the gate side of the 2030 (this is the left-most leg when looking at the face of the ERF-2030).
the other end to positive side of c116. that will bring your dk to about 6 watts oterwise your dk will be about 3watts..........theres a way to volt the pre-driver but i only know the cobra 25 mod.....no one seems to want to give the info for the 29
i have gotten better performance with the cap
I was talking to a CB repair guy in Utah and this is his mod for the 2030. He says it will let a radio bark.
-Remove C61
-Remove r55and r58.
-Replace R56 with the EN 1230
-Piggyback C59 with a 68pf cap
-add 2 33pf caps across C62
-place a jumper across R123
-Remove jumper JP32
-Jumper from L15 to L17 (he explained this as going from the end of the JP32 jumper that has the two contact points real close together, to the thin strip that is connected to the anti spike diode)
-jumper from gate of 2030 to the positive of EN 1230.
Let me know what you guys think.
Also, would I also add the 4.7pf from the gate of the 2030 to C116 or skip this?
-Remove C61
-Remove r55and r58.
-Replace R56 with the EN 1230
-Piggyback C59 with a 68pf cap
-add 2 33pf caps across C62
-place a jumper across R123
-Remove jumper JP32
-Jumper from L15 to L17 (he explained this as going from the end of the JP32 jumper that has the two contact points real close together, to the thin strip that is connected to the anti spike diode)
-jumper from gate of 2030 to the positive of EN 1230.
Let me know what you guys think.
Also, would I also add the 4.7pf from the gate of the 2030 to C116 or skip this?
Also, I have had my radio peeked, tuned and aligned with the stock CB tricks mod. After the additional moding, will I have to have it P&T'ed again
funbiz99 said:i dont quite understand? are you adding a 15k & 33pf cap where r55 was??DTB Radio said:The thought is ok, but woukd entail some major redesign, as well as major new design. In the FET mods that I've done (cobra 29's primarily), I see carrier levels of around 5 to 6 watts, with my Wavenode system regularly recording 40 to 45 watt peaks. I've had customers come back after having the EFT mod done and tell me they walked on guys running amps. The only things I do differently from the cbtricks procedure is use higher cap values, change the driver base input resistor to 4.7 or 3.9 ohms, and add a 33pf cap to the spot where the 1k resistor is removed (i forget the number right now, its near the antenna socket by the SWR bridge circuit). Oh, I usually replace that 1k with about 15k so there's still bleed-off for any static electricity that might be building up.
thanks
Yes, thats what I meant
Xy3lon4 said:Also, would I also add the 4.7pf from the gate of the 2030 to C116 or skip this?
That was a 4.7k resistor, not a 4.7p cap, unless I'm really in nead of reading glasses.
DTB Radio said:Xy3lon4 said:Also, would I also add the 4.7pf from the gate of the 2030 to C116 or skip this?
That was a 4.7k resistor, not a 4.7p cap, unless I'm really in nead of reading glasses.
4.7k resistor...exactly and this definetly is what brings the dead key up!!!!!!
No, I'm the one that is blind. Thanks for the clarification.DTB Radio said:Xy3lon4 said:Also, would I also add the 4.7pf from the gate of the 2030 to C116 or skip this?
That was a 4.7k resistor, not a 4.7p cap, unless I'm really in nead of reading glasses.
So would the jumper from the gate of 2030 to the positive of 1230 be a good idea?
funbiz99 said:Put a 4.7k 1/2 watt resistor on the gate side of the 2030 (this is the left-most leg when looking at the face of the ERF-2030).
the other end to positive side of c116. that will bring your dk to about 6 watts oterwise your dk will be about 3watts..........theres a way to volt the pre-driver but i only know the cobra 25 mod.....no one seems to want to give the info for the 29
one more time the above will raise your dk from appx 3watt-5watts bird
So will the mod that I mentioned fly or will it smoke my radio?
The only thing I am worried about is the jumper from the ERF 2030 to the EN 1230 I think he said base leg but he might have said gate leg.
The only thing I am worried about is the jumper from the ERF 2030 to the EN 1230 I think he said base leg but he might have said gate leg.
Yea it looks good....The only part you have to be carefull with is jumping L15 to L17...What your doing there is jumping in power.... removing JP32 is removing the 8 volt power to the predriver. The whole idea here is tol remove the power to this part of the rf amp and add it in from another.
The thing with doing this is....the 8 volt power to the "buffer" transistor is switched... on during transmit and off during rx mode.
As long as the mod he does lets the new power be switched the mod it ok.
I've done it with constant power, but its not something I would recommend.
The other thing is removing r58...... R58 is the only way the rf "drive " from the buffer can get to the driver. It needs some sort of a connection between the buffer and pre driver.
I can't see why he would add in voltage to the buffer only to remove it... unless he was trying tojump the output from the buffer from L17 to L15, but I can't see why he would want to do that.
It looks like he increased power to the buffer and tried to increase the drive to the driver by perhaps REMOVING R58 and replacing it with a jumper. By just removing R58 you are leaving the driver and buffer unconnected.
It looks like he did the same thing with R123... he took out that resistor and replaced it with a jumper.... this resistor is between the final and driver and is jumped out to get more drive to the final.
R123 and R58 are usually changed to get more drive into the driver and final transistor... Jumping both of these out seems OK. But I would not remove r58 without adding in some sort of jumper.. there is no other way to get power from the buffer but through this connection.
The extra caps your adding in is just extra coupling which is cool... R55 is ok to remove also.
The only change I would make in this mod is maybey changing the value of R58 to a lower value.... or just jumping it out.
Also when you do jump power into L17... remove JP32 first.
The only thing I would recommend is to check that the power to the buffer is switched after you do this. My radio I've used for about 1 year has constant power going into it.... but switched power would be the better way to do it... After adding in constant power I've had a couple of resistor brown out on me. Its best to keep the radio running like it was designed to... switched power would be better.
Take care
The thing with doing this is....the 8 volt power to the "buffer" transistor is switched... on during transmit and off during rx mode.
As long as the mod he does lets the new power be switched the mod it ok.
I've done it with constant power, but its not something I would recommend.
The other thing is removing r58...... R58 is the only way the rf "drive " from the buffer can get to the driver. It needs some sort of a connection between the buffer and pre driver.
I can't see why he would add in voltage to the buffer only to remove it... unless he was trying tojump the output from the buffer from L17 to L15, but I can't see why he would want to do that.
It looks like he increased power to the buffer and tried to increase the drive to the driver by perhaps REMOVING R58 and replacing it with a jumper. By just removing R58 you are leaving the driver and buffer unconnected.
It looks like he did the same thing with R123... he took out that resistor and replaced it with a jumper.... this resistor is between the final and driver and is jumped out to get more drive to the final.
R123 and R58 are usually changed to get more drive into the driver and final transistor... Jumping both of these out seems OK. But I would not remove r58 without adding in some sort of jumper.. there is no other way to get power from the buffer but through this connection.
The extra caps your adding in is just extra coupling which is cool... R55 is ok to remove also.
The only change I would make in this mod is maybey changing the value of R58 to a lower value.... or just jumping it out.
Also when you do jump power into L17... remove JP32 first.
The only thing I would recommend is to check that the power to the buffer is switched after you do this. My radio I've used for about 1 year has constant power going into it.... but switched power would be the better way to do it... After adding in constant power I've had a couple of resistor brown out on me. Its best to keep the radio running like it was designed to... switched power would be better.
Take care
So here is the mod.
Still I don't know about the jumper from ERF 2030 to EN 1230. I was looking at my notes and I think he said from the base leg of the final to the positive side of the EN 1230 Should I just leave this out? Also, I changed the 2 33pf caps to 1 68pf cap for simplicity.
Please check this and make sure that I have gotten the legs of the mosfet correct. Wouldn't want to accidentally mix up the base leg and the gate leg.
Anyway, in this order.
-Remove jumper JP32
-Remove C61
-Remove R55
-Remove tuning slug from L14
-Jump out R58
-Replace R56 with the EN 1230
-Piggyback C59 with a 68pf cap
-Add a 68pf cap across C62
-Jump out R123
-Place jumper from the end of L15 closest to the front of the radio to L17 (he explained this as going from the end of the JP32 jumper that has the two contact points real close together, to the thin strip that is connected to the anti spike diode)
-jumper from base leg of ERF 2030 to the positive of EN 1230.
-add the 4.7k resistor from the gate side (left leg) of the 2030 to positive side of C116
Still I don't know about the jumper from ERF 2030 to EN 1230. I was looking at my notes and I think he said from the base leg of the final to the positive side of the EN 1230 Should I just leave this out? Also, I changed the 2 33pf caps to 1 68pf cap for simplicity.
Please check this and make sure that I have gotten the legs of the mosfet correct. Wouldn't want to accidentally mix up the base leg and the gate leg.
Anyway, in this order.
-Remove jumper JP32
-Remove C61
-Remove R55
-Remove tuning slug from L14
-Jump out R58
-Replace R56 with the EN 1230
-Piggyback C59 with a 68pf cap
-Add a 68pf cap across C62
-Jump out R123
-Place jumper from the end of L15 closest to the front of the radio to L17 (he explained this as going from the end of the JP32 jumper that has the two contact points real close together, to the thin strip that is connected to the anti spike diode)
-jumper from base leg of ERF 2030 to the positive of EN 1230.
-add the 4.7k resistor from the gate side (left leg) of the 2030 to positive side of C116
When looking at the front, the three legs of the ERF 2030 are, from left to right; gate, drain and source. I don't know what the CB repair guy meant by "the base leg" please help me out on this. which leg would I jump to the positive of the EN 1230?
Xy3lon4 said:When looking at the front, the three legs of the ERF 2030 are, from left to right; gate, drain and source. I don't know what the CB repair guy meant by "the base leg" please help me out on this. which leg would I jump to the positive of the EN 1230?
With the thing facing you, the left leg should be the base.
That is what it looks like on the spec sheet for a 1969 final.
pin 1 - base
pin 2 - collector
pin 3 - emitter
From left to right.
After I posted, I found a spec sheet of sorts for the ERF 2030 and the legs are definitely gate drain and source. Is base another name for the gate leg? Until I get confirmation on the jumper from the 1230 to the 2030 I am going to leave that out.Librium said:Xy3lon4 said:When looking at the front, the three legs of the ERF 2030 are, from left to right; gate, drain and source. I don't know what the CB repair guy meant by "the base leg" please help me out on this. which leg would I jump to the positive of the EN 1230?
With the thing facing you, the left leg should be the base.
That is what it looks like on the spec sheet for a 1969 final.
pin 1 - base
pin 2 - collector
pin 3 - emitter
From left to right.
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