can someone help me find the L10 pot ????? or lead me too some pics thanks heck all i want my too do is 2w dk and 10w swing so i should have no probs !
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still cant find can u show me a pic thanks maybe my radio is diff? the ony one i see there has a vr5 number on it
It's not a VR, it's a vertical coil.
This could help.
http://www.cbtricks.com/miscellaneous/fet_papers/ekl/graphics/erf2030_cobra_25_mod.pdf
This could help.
http://www.cbtricks.com/miscellaneous/fet_papers/ekl/graphics/erf2030_cobra_25_mod.pdf
I just read through all this again...... I think you misunderstood what I was saying. Let me clarify ( months later LOL)
If I used a single 1969 and hitting 50 watts peak from low carrier... its going to be overmodulated.
The last part of my post says that I do a similar mod with a 1446 ( or 2879) that hits 50 watts peak.... but I get about 20 to 30 watts carrier. When I do the mod this way its fairly clean but modulation isn't screaming loud.... I thought thats what you were refering to.
3 watts swinging to 50 watts is a crappy radio.... harmonics... reactance..,. etc.
If I use a bigger transistor I can get it decently clean.... BUT with a single 1969..... forget it... no way its clean or even worth while.
Anyhow... 1969 50 watts peak is crappy in my opinion ( I agree with you) but with a larger transistor and more carrier its not bad and can be decenty clean.
I should have read your post better......
dtb,
When using the 2030 mosfet upgrade have you ever used the diode and two resistors thing at r 40 ...(I think this is where the other component goes.) instead of the elk component..
When using the 2030 mosfet upgrade have you ever used the diode and two resistors thing at r 40 ...(I think this is where the other component goes.) instead of the elk component..
99.99999999% of these radios sound best before they are hacked into oblivion. a bit of tweaking here, a parts change there & maybe just a mild modding & you will have audio like no CBer in the land has.....because they hack the crap out of everything & get 40-50 watts out of 22 watt devices. even a galaxy/clone export can be made to sound decent & clean if not cranked to the max. 50 watt CB's don't excite me. a class 'C' splatter box can be made to sound half way decent when driven with restraint. 50 watts is too much for the driver & not enough for the big box, so why waste the time? because you THINK a 50 watt CB is gonna blow away a more civilized radio? i wouldn't make that bet.
B
BOOTY MONSTER
Guest
none of you here (with the possible exception of Dave) have stopped long enough to understand a few things. first of all, the 1969 is rated for 18 - 22WPEP in CLASS AB OPERATION. the PA in the 68 IS NOT OPERATING CLASS AB. the second point is that the peak-to-peak collector voltage is much higher than the rail voltage when the stage is modulated not to mention the flywheel effect created by the resonance of the pa tank and the reinforcement provided by the reverse emf. in addition to all of the above the input impedance looking into the original 2SC2078/2SC2166 and the output impedance into the pa tank both have to be modified if the 2SC1969 is going to produce more output power than the oem device because these impedances differ between the two devices. this is exactly why only replacing the 2078 with the 1969 and nothing else yields no dramatic increase in power output.
with regard to modulation index, 100% modulation of the transmitted signal occurs at the point where the peak envelope power approaches four times the resting unmodulated carrier or 6db. increase in power output. ratios in excess of 4:1 produce excessive modulation and ratios less than 4:1 produce an undermodulated signal.
dB = 10 LOG(1 + M)2
db = 10 LOG(1 + 1)2
db = 10 LOG(2)2
db = 10 .602
db = 6.02
why anyone would want to measure average power is beyond me since the 1969 is rated in PEP. if that is your preference then make sure you understand the relationship.
dB = 10 LOG(1 + (M2 / 2) )
db = 10 LOG(1 + (1 / 2) )
db = 10 LOG(1 + (.5) )
db = 10 LOG(1.5)
db = 10 .176
db = 1.76
a 1.76 db. increase in power output corresponds to an average-to-carrier ratio of approximately 1.5:1 when measuring average power output. wrap your head around this for a while and you'll begin to understand what is doable and what isn't.
the spectral purity of the outputted signal doesn't have to suffer while attempting to increase efficiency if additional low pass filtering is implemented.
first you have to have a clear understanding of what's going on "inside the box" before you can begin to think outside of it.
with regard to modulation index, 100% modulation of the transmitted signal occurs at the point where the peak envelope power approaches four times the resting unmodulated carrier or 6db. increase in power output. ratios in excess of 4:1 produce excessive modulation and ratios less than 4:1 produce an undermodulated signal.
dB = 10 LOG(1 + M)2
db = 10 LOG(1 + 1)2
db = 10 LOG(2)2
db = 10 .602
db = 6.02
why anyone would want to measure average power is beyond me since the 1969 is rated in PEP. if that is your preference then make sure you understand the relationship.
dB = 10 LOG(1 + (M2 / 2) )
db = 10 LOG(1 + (1 / 2) )
db = 10 LOG(1 + (.5) )
db = 10 LOG(1.5)
db = 10 .176
db = 1.76
a 1.76 db. increase in power output corresponds to an average-to-carrier ratio of approximately 1.5:1 when measuring average power output. wrap your head around this for a while and you'll begin to understand what is doable and what isn't.
the spectral purity of the outputted signal doesn't have to suffer while attempting to increase efficiency if additional low pass filtering is implemented.
first you have to have a clear understanding of what's going on "inside the box" before you can begin to think outside of it.
the point freecell was making is....go to co**er, buy a radio & have them 'expand' it WITHOUT hacking the crap out of it, buy a dx667v or 500 & go to town! you'll be AMAZED at how GOOD it really sounds.
might not key over my driver box, but at least they'll be able to understand you when i unkey.
sorry if i took some liberties with your explanation freecell, but i oversimplified it for 74IN, i think he gets it now.....ROFLMAO!
might not key over my driver box, but at least they'll be able to understand you when i unkey.
sorry if i took some liberties with your explanation freecell, but i oversimplified it for 74IN, i think he gets it now.....ROFLMAO!