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What have I done wrong (Mosfet Conversion)

sonoma said:
I have a hard time sleeping. I only sleep about 2 hours a day in most cases. some time I will go 2 days with out sleep. I search through the forums all the time since my wife is sleeping. I am retired now so not much sleep for some reason. when I use to work I was on night shift and would get home about 6 AM and would go to bed and be up at about 9 to 10 AM and then go out and do things out side then head back to work at 4 PM. Doctors say I need to sleep more but I have not been able to sleep much since about 1980.
I just got where that is all my body wants to sleep. they have even tried giving me sleeping pills and it did not work.
hopefully with the last item I left you will help you get it going.
also you might even try the little ceramic insulators behind the finals. the factory thin ones do not work real good on the mosfet change. they cause a capacitance problem on some radios and the ceramic ones help to take care of the problem. Rick from euro radio that helped Bennie with these mods told me this when I was putting dual finals in a texas ranger 696fd1 radio. would not swing past 20 watts with dual finals and the flimsy insulators. put the ceramic in it and it would swing over 40 watts. I was surprised at this.
just some thing you might think about since you are doing the mod.
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I feel you on the lack of sleep issue.
I had brain surgery back in 1998 and that did it for me.(they found none) Since then I have had constant headaches 24/7/365. Hard to sleep when you have the Iron Butterfly light show going on behind your eyelids. It never goes away, just fluctuates in intensity. Typical migraine symptoms with vision disturbances, sensitivity to light and loud noises. All of my vehicles have quiet exhaust and radios are not turned up any louder than necessary to hear the music or voice.
 
Damn, Sonoma can't sleep, they didn't find your brain and now you have severe headaches, I feel bad for both you guys.

Don't feel bad, from my postings I'm sure I don't have any brains either.

Were you talking to me or him about the jumper?
 
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TheRealPorkchop said:
Damn, Sonoma can't sleep, they didn't find your brain and now you have severe headaches, I feel bad for both you guys.

Don't feel bad, from my postings I'm sure I don't have any brains either.

Were you talking to me or him about the jumper?
Click to expand...
Whoever is doing the modification. I have heard this problem before. The designer of the modification may have missed putting in a jumper to bridge the circuit of a component that was removed. Maybe a coil or a resistor that has been taken out of the bias circuit and not replaced with a jumper.
 
I don't know if I was read the diagrams right in section three, but it shows both diagrams as being dual finals to start with.
I went back and looked at it again and this is mod to replace Bipolar transistors with Field Effect Transistors.
 
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Now that you mention it, seems like I read somewhere about them not testing it on but one type board and something being overlooked too. I'll have to go back and look at what I've done.
 
on the 959 radio there is a jumper you have to put in for jp91 . this ties the 2nd final to the circuit. I know when the mod 1st came out that was missed on this radio
 
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Tallman said:
I don't know if I was read the diagrams right in section three, but it shows both diagrams as being dual finals to start with.
I went back and looked at it again and this is mod to replace Bipolar transistors with Field Effect Transistors.
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I know, I want him to make his final section nearly identical to page 9 :p

Note: the ssb radios have adjustable driver bias, normally this is a fixed stage in the single final only radios, "mod accordingly" lol; I have added the driver configuration from a DX88HL to a (still single final) Connex 3300, results are pleasing in terms of adjustability (linearity)!

I have a DX66V that is begging for dual mosfet conversion, TheRealPorkChop is gonna have me chasing the watts! lol
 
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Check List for ept3600 dual final conversion using BJT's and MV1Y's.
[photo="medium"]4888[/photo] .

Source: http://www.angelfire.com/electronic/cbdoctor/dualfinalconv.html
Below, you will find the RF output circuit for the single output stage such as the Connex 3300, the Galaxy DX-33 and the DX-44 and the RF output circuit for the double output stage such as the DX-88 and DX-99. The various units will vary somewhat from these schematics but using these versions will work in any of the units that use the ept360014B pc board.

Armed with this information, along with a my visual layout, it becomes an easy task to convert a single-ended unit to a dual final unit.
Click to expand...
 
Well, it's not hard to convert a single to dual especially if you have a donor radio laying right beside it. I've been there and done that, that's no big issue. It's not really that big an issue if you have a schematic or if you're just a super genius (which I'm not). The problem I've been experiencing is just a lack of dead key or carrier. I've gotten it about sorted out I think but I'm not really that impressed with it and I know it'll do a little more, though most likely not worth it.

Far as a project goes, it's fun but I do believe it's a total waste of time, haha.
 
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I'll bring my dead thread back from the grave...this way I won't clutter up another section with another question that's probably been answered already 10,000 times.

I finally sorted that radio out but sadly I don't remember what I did to get it to work. If I remember correctly, I only got about a 1 watt carrier out of it but it finally did hit the PEP mark of 40 watts. Like I said, a waste of time. So...

I've got a 77HML that needs some transistors replaced. I've been thinking about just using mosfets since they're cheap and I have a 5 gallon bucket of them, 13n10's and 520's... and a handful of 2030+'s that I think are useless. So my question is : can you drop mosfets in that board and not add those darn companion parts? Every time I build a companion part, it's too big and bulky and looks like sheet. Can't you just use the VR's that are in the radio to adjust the bias voltage without those ding-dang companion parts?

Eric Lewis needs to get to hoppin' and build up some more of those companion parts and somebody needs to tell me what actual use those 2030+ parts have cause I have yet to find a good use for them. 13N10's, pretty good parts and 520's are pretty good parts, if you have the 369/1230 parts to use with them. So who has input here that can help me out with this, it's looking like Eleflow 2312's are in my future or I'll be forced to use 1969's from RFP.

Input...
 
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Bias trimpots, and other input-side resistors will have to be changed to match the gate of a MOSFET. The BJT base circuit is low-impedance, the MOSFET gate is high.

I'm skeptical of the 'companion' parts. They serve to rectify the needed DC gate-bias voltage from the drive carrier. They don't sound so good for SSB, without that trimpot. For an AM-only radio it's a lot less complex than building a trimpot-controlled bias circuit. Should not be any need to use both at the same time.

Don't think so, anyway.

73
 

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