| Author |
Message |
    
Pmktsc1
| | Posted on Sunday, November 09, 2003 - 2:05 pm: | 
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looking for modifications for modulation.Also wireing for internal speaker. |
Kc0gxz
| | Posted on Monday, November 10, 2003 - 6:00 pm: |
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Pmktsc1
I hope this will help you.
VR14-AMC
VR13-AM High power
VR15-AM Low power
VR12-SSB high power ALC
VR16-SSB Low power ALC
Jeff, kc0gxz. |
Bullet
| | Posted on Wednesday, November 12, 2003 - 11:49 pm: |
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if its the older version look at r281 you can do a diode swing mod here that really sounds good and strong with out getting trashy.
you can also rebias the mod limiter at r 178 ill have to look at my 2950 pages to remember the value of the resister to replace it with.i think 2.2k to 3k will do the trick
there is also the swing mod by the am modulator that uses a 50 ohm resister and a 914 diode.
ill look these up for exact details and post back |
Bullet
| | Posted on Thursday, November 13, 2003 - 1:27 pm: |
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yah here we go
1, you can go to r285 and do a swing mod thier by adding a 1n914 diode cathode side to a 3.3k ohm resister and install this in parallel with the existing 470-560 ohm resister. this is done on the foil side of the board.this is near the am modulator.
2,this is the mod i like better.(thanks John M)
go to r178 (4.7k)replace this with a 2.2k-3.3k ohm resister.this rebias the mod limiter.
then you can go to r281 and lift the far leg of this resister and add a 1n914 diode cathode side to resister and resolder other side of diode were the resister went to the board.
you can also replace r281 with a 2.2k-3.3k resister if youd rather do this instead of the diode trick there.
i also replace Q51 with a 2sb817 and replace Q53 with a 2sa 1012.
this as well makes these radio's run a bit cooler and the modulation is nicer. and you might get a couple of watts maybe out of it,nice side effect but its not a power mod so dont expect a huge differance in wattage..
look at the vr's in above post and adjust radio for good modulation without going over board i like 90-95% not more than 100%. and youll be booming and the limiter will still funtion if need be.
try to keep hi dead key at 8 watts no more than 10 on the high side. low i set mine at 2 watts and i strive for a swing ratio of between 1:4 to 1:6. like 5watts swinging 20 or 5 swinging 30.
my 2950dx keys 4 swings 20 on the bird 43p
my 2950 old style with mrf497's does much better.
hope this is usefull
later bullet
thats my |
Pmktsc1
| | Posted on Saturday, November 15, 2003 - 1:35 am: |
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THANKS THERE GUYS!! SORRY IT TOOK ME SO LONG TO GET BACK ON HERE. |
Tallman
| | Posted on Saturday, November 29, 2003 - 12:54 pm: |
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Hi,
Does this mod info pertain to the newer Rci-2950Dx? I need mods for it.
Thanks, Tallman |
Bullet
| | Posted on Wednesday, December 03, 2003 - 9:29 pm: |
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tallman,
they are for the older model.
the new one is smt you could swap the am modulator to the 2sb817 and adjust the vr's your self.
but you really need to be setup for smt's to do alot of modifications like said above for the dx models. |
Tallman
| | Posted on Wednesday, December 10, 2003 - 9:21 am: |
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Ok Bullet,Thanks & Happy Holidays!
T-man |
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