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Message |
    
Airplane1
Advanced Member
Username: Airplane1
Post Number: 518
Registered: 5-2004
| | Posted on Monday, August 01, 2005 - 8:07 pm: | 
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I have my grant xl tuned down to 1-1/2 watt dead key, since I did this it only swings up to about 3 watts when talking. is there a adjustment for swing on this radio?
thanks,
AP |
Vanillagorilla
Intermediate Member
Username: Vanillagorilla
Post Number: 122
Registered: 4-2005
| | Posted on Tuesday, August 16, 2005 - 8:51 am: |
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L37 & L38...Turn your AM power up to around 10 then work with these two...Mainly L37 to adjust DK swing. You'll be going back and forth between VR and L37 but you'll get your swing. I could get mine so low it looks like I'm sideband..(1/2watt swing to 8 or 10) I've since readjusted to a 4dk swing to 14. Any higher on the dk and RMS swings backward. Are you using a power mic? Is the Mic gain on the radio turned up? These things will effect overall swing...the more modulation the more swing you'll see.
Hank '905
CEF559 |
Al_lafon
Member
Username: Al_lafon
Post Number: 71
Registered: 3-2005
| | Posted on Thursday, August 18, 2005 - 12:22 am: |
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Hay i don't get this big swing thing i have always set the radio to 4 or 3 1/2 then on a scope looked for best mod. and watts out with
out over modulation can you tell me why your not
using a scope. as far as i know your over modulation when doing that setup ? |
Nobodyknows
Member
Username: Nobodyknows
Post Number: 68
Registered: 4-2005
| | Posted on Thursday, August 18, 2005 - 3:14 pm: |
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I hear these big swinging radios all the time here, (i live between 2 interstates) They sound like pooptiededoo. I see them on my S meter going from 1/4 pound swinging to 9 pounds. They distort pretty bad and get walked on/coverd up by weaker radios that maintain a 7 pound reading on my meter. Higher DK like 3 or 4 watts sounds better than the 1/4 watt DK guys any day. Just my opinion.. |
Magnetron
New member
Username: Magnetron
Post Number: 3
Registered: 6-2005
| | Posted on Thursday, August 18, 2005 - 4:09 pm: |
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About the only advantage that I can see with a low DK and high swing is that when your keyed down and not talking, your saving energy (lower power = lower energy consumption). Aside from that, a DK 1 watt carrier with swing to 16 watts at 100% modulation is the same as a DK 4 watt carrier swing to 16 at 100% modulation. Assuming the radio isn't clipped cause then it's overmodulation and overmodulation = splatter...etc and something I never heard it called before, a "pulsed spectrum" http://www.williamson-labs.com/480_am.htm |
Tech808
Moderator
Username: Tech808
Post Number: 6716
Registered: 8-2002
| | Posted on Thursday, August 18, 2005 - 4:29 pm: |
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Magnetron,
Thank You, for the very helpful, informative Link. 
Have you read about our CEF Radio Club yet?
Lon
Tech808
CEF808
N9OSN
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Airplane1
Advanced Member
Username: Airplane1
Post Number: 541
Registered: 5-2004
| | Posted on Friday, August 19, 2005 - 7:20 am: |
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I only wanted to know cause right now mine is set to 2- 2 1/2 dk to run with my KL500 but the grant barely swings to 4 watts when talking. my 696FD1 swings very nice as it came from factory. I just wanted to make it swing up to say 10 watts, the radio is stock as it came from factory with only thing changed was I turned the DK down myself for running my KL500. I just thought it should swing more than 4 watts. Am I wrong and the radio is fine or should it swing more?
Thanks,
AP |
Vanillagorilla
Intermediate Member
Username: Vanillagorilla
Post Number: 137
Registered: 4-2005
| | Posted on Friday, August 19, 2005 - 10:56 pm: |
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Sorry about getting back to this topic so late! Where's "00" when you need him? 
To answer your question...YES..you should be easily getting more than that out of your Grant. The only mod done to mine was the clipping of Q24 by the previous owner. I will say this..I'm not a fan of clipping if there are other alternatives BUT clipping Q24 on yer Grant(or TR24 on a 148GTL) really makes these radios come alive! The PEP readings I mentioned earier where achieved with the stock mic no less! Even on a non peak reading meter I can see it swing from 1/2w to 5. Like I said I've since brought it back up to 4w DK but was looking forward to running it with an amp till wifey found another use for my money  . A friend of mine did the resistor swap on his and its a screamer. He can't use a power mic unless he turnes down the mic gain to 12:00...squeal city..plenty loud with the stocker although maybe lacking a little "body" to the modulation. Not quite like clothes pins on the nose but not as much beef as a well adjusted power mic like the Astatic 575 or DM452.
I don't "YET" have access to a scope but truly strive for CLEAN modulation. I get checks VERY frequently and will ask how it REALLY sounds and I don't stop until I'm told "clean". Scope or not...I try. I don't wanna rule the town and splash 2 channels over and I don't wanna sound like some of the clip and ship "drivers" I hear every morning with the echo and power mic set at "11" . If some people could learn to turn the power down sometimes they would not believe how much better they sound....really!
NOTHING wrong with some swing. Swing is what makes you sound louder but as mentioned above too low is just silly unless you wanna drive something larger .
DISCLAIMER: Not telling ANYONE to clip ANYTHING..just the facts is all. Would I clip? Dunno..I'd do the resistor swap first. BUT..on some rigs it works great...(if you can sleep at night knowing someone /somewhere is hearing you "splash". [Flame suit "ON" ]
Hank '905
CEF 559
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Patzerozero
Senior Member
Username: Patzerozero
Post Number: 1269
Registered: 7-2004
| | Posted on Saturday, August 20, 2005 - 11:00 pm: |
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your radio is stock, airplane, it is fine. want to mod it? you ready, here goes!
1- cut trace to leg & add 1.5k resistor to middle leg of tr24.
2- replace r126, r124, & r131 with 4.7k resistors
3- adjust vr10 for 2-3 watts(or wire to variable)
4- solder positive side of 10uf 35 volt cap to pin 9 of ic6
5- solder negative leg of that cap to junction of r271-d63-r228-put tubing/insulator over legs to prevent shorting.
6- turn vr10 wattage down as low as it will go
7- clip TP8 & tape ends.
8- on trace side of board, solder heavy wire from junction c148/L39(on older boards, it's c146/L39), to 13.8 volts at junction of c188/d55/red wire/input coil
9- jumper r196
10- readjust vr10 for 2-3 watts, unless you put it on external variable, then adjust it there for 2-3.
if your radio was working well to begin with, your XL/LT/148/texas ranger 296/general sherman should now be dead keying 2-3 watts into your antenna & swinging 20 give or take on a peak meter, or 10 or 11 or so on a rms/avg meter(the infamous 'bird watt' reading). there are current bias adjustments that can be done to the driver transistor & final transistor as well, but should not be neccessary, unless you needed to replace those transistors(due to failure) or a magic screwdriver had already fiddled with them. if 1 had, you'd either have suffered that above mentioned failure already(too high) or you would have real weak dead key output(too low). if you want those adjustments, let me know & i'll post 'em.
in step 1, you COULD remove tr24 altogehter, (clipping the limiter) & the mic gain adjustment would be needed to be backed down to prevent overmodulation & a power mic will NOT be neccessary-it will be LOUD. swing will probably increase another 2-3 pep, maybe 1 rms, so it's not neccessary to remove as gain is minimal.
i've done this mod A LOT of times. dead key is unaffected as far as that goes-the spread remains at factory tolerances of 0-6 watts, with most just topping 5 watts. as for PEAK swing, i've gotten as high as 25 watts, with most being at or around 20. & rms/avg swing always at least 8 up to as high as 13.
HAVE FUN
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Airplane1
Advanced Member
Username: Airplane1
Post Number: 544
Registered: 5-2004
| | Posted on Monday, August 22, 2005 - 7:27 am: |
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Wow, lots of stuff/LOL! maybe i`ll just leave it alone and stock. I dont want to screw it up since I bought it new and did`nt use it much. hate to mess it up.
thanks for the info.
AP |
Patzerozero
Senior Member
Username: Patzerozero
Post Number: 1289
Registered: 7-2004
| | Posted on Monday, August 22, 2005 - 12:23 pm: |
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of course you could always just CLIP THE LIMITER! that's just 1 snip to middle leg of Q24....that's the cheap & easy way to get the meter to show some swing. but DEFINITELY NOT the preferred method! you are NOT be adjusting any coils or anything inside the radio to cause a problem. you just have to make sure what you are cutting or soldering is correct before doing it. i did all the above mods to mine including clipping q24, but it is on a switch so it can go into the circuit for local talking.
look around for a used xl/lt/148(even a new china 148) if you can get it cheap enough. then you can open THAT ONE up & examine its insides. not really all that hard to do. there are also 3 or so GOOD receiver mods that can be done to it, as well as opening the clarifier & adding channels. i understand not wanting to make YOUR radio the guinea pig! |
Kid_vicious
Advanced Member
Username: Kid_vicious
Post Number: 517
Registered: 9-2004
| | Posted on Monday, August 22, 2005 - 10:46 pm: |
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hey pat, you gettin' tired of posting that mod yet?LOL
seems no one knows that their grant xl is the same as the 2000gtl and the 148gtl on the inside.
i have a couple of questions about your version of the mod.
on other sites i have seen the NPC mod (the 10uf cap on the audio IC) done a bit differently.
the positive side still goes to pin 9 of IC 6, but the negative leg goes to the junction of R194/D63/R228. i noticed that you put it somewhere else. any particular reason for this?
just curious.
also, you recommended replacing R131 with a 4.7k resistor. since the stock part is a 10k (pretty sure), and clipping it increases modulation, i would think that increasing the resistance of this part would be the recommendation, like maybe 100k ohms. mine is on a switch that either opens it up or adds the stock 10k.
airplane1, try this, it's simple and will give you some swing.
remove C207.
replace R206 with 33-39k. (anything within this range will work.)
add 1k resistor to middle leg of TR24.
using a plastic tuning tool (available at rad shak).
key mic on ch.19 or 20
say, "aaahhhhhh" into the mic as you SLOWLY turn L47. the s meter on your radio will move to the left. keep turning L47 until the meter is as far over to the left as it will go before it starts backing down. you must do this WHILE you are speaking into the mic.
repeat this process for L48, L46, L45, and finally L38. (L38 will look different and will need a different tuning tool. do not turn the other coil that looks like L38, it is your TVI coil and is already set with equipment you and i cant afford.)
now find VR10 and turn it down until your dead key is between 2-3 watts. no more than 3.
this should allow you to swing upwards of 8-10 watts.
you can go further, but this will work for you. |
Airplane1
Advanced Member
Username: Airplane1
Post Number: 545
Registered: 5-2004
| | Posted on Tuesday, August 23, 2005 - 9:06 am: |
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Thanks Patzerozero and Kid vicious,
I am printing these posts you gave for modding the Grant and going to study them and try to get up nerve to do some or all of them.
Wish me luck/LOL!
AP |
Kid_vicious
Advanced Member
Username: Kid_vicious
Post Number: 521
Registered: 9-2004
| | Posted on Tuesday, August 23, 2005 - 7:18 pm: |
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airplane1, just so you know, i got my mod info from pat. the info is good and the mods work well.
if you want to see exactly what was done to my 2000gtl(same board as your grant) check out my post titled, "my 2000gtl".
i am very happy with the way my radio sounds, and the next step is to put some channels in it.
BTW, the advise about getting another radio to experiment with is very sound.
matt |
Patzerozero
Senior Member
Username: Patzerozero
Post Number: 1299
Registered: 7-2004
| | Posted on Wednesday, August 24, 2005 - 8:29 am: |
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'hey pat, you gettin' tired of posting that mod yet?LOL
seems no one knows that their grant xl is the same as the 2000gtl and the 148gtl on the inside'-well, i do it so often i HAVE IT MEMORIZED! don't forget that'the same inside' include 2000/148/XL/LT/TR296/general sherman/radio shack/others. i've NEVER done the radio shack, nor ever owned 1 so i always forget which model#! that & 2 or 3 other radios i've been told of!
i have 7-YES SEVEN- of those radios waiting for a rainy day laying around right now. you asked a good question & i don't know the answer. i have my 'original copy' of the mod written down from the EARLY 90's & that's what it says. the r131 part is a compromise, either 'clip it' or add to the modulation by LOWERING resistance 50%(clipping it is lowering resistance 100%), & have only half the chance of overmod & splatter...
next 1 i open, i'll look & see what the diff between r194 & r271 is.
you can change the cap on ic 6 to 50 volts also, & experiment with different values, other then 10uf. it'll change amount of compression/sound of radio. 10uf is good when NOT using scope, if you have 1, experiment up & down to see if you can get more negative compression, without it affecting positive peaks or totally removing negative as well as audio quality.
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Vanillagorilla
Intermediate Member
Username: Vanillagorilla
Post Number: 145
Registered: 4-2005
| | Posted on Wednesday, August 24, 2005 - 6:09 pm: |
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Two things...Pat mentioned TR24 and as I've stated earlier as "far as I know" thats a Cobra part # as the Uniden Grant mod limiter is labeled "Q" 24...I'm SO SURE it was just an oversite by Pat..With the radio "belly up" its about an inch behind the meter..lil black 3 legged bug.
As another side thing..PAT...you mention the "MIDDLE" leg of Q24..is there a reason for the middle leg to be clipped? I noticed the rearmost and NOT the midle is clipped on mine. Make a difference?
Thanks~
Hank '905
CEF 559 |
Patzerozero
Senior Member
Username: Patzerozero
Post Number: 1302
Registered: 7-2004
| | Posted on Thursday, August 25, 2005 - 8:52 pm: |
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'Q' is the standard symbol for transistor on a schematic diagram. for some reason, the OLDER radios used 'TR' to stand for transistor, & the newer ones adopted the 'Q'. NO DIFFERENCE.
as for which leg is clipped, it doesn't make a difference in actual performance of the radio, however clipping the middle leg eliminates the circuit 'sooner'. the end leaves 'non-used circuitry' still functioning-just not doing anything. |
Kid_vicious
Advanced Member
Username: Kid_vicious
Post Number: 534
Registered: 9-2004
| | Posted on Friday, August 26, 2005 - 12:37 am: |
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man, i feel kinda dumb. i looked at my schematic, and you're right pat; clipping the resistor lowers the resistance 100%.
thanks for the tip on the cap. i am very interested to see what comes of my question. |
Sg569
Intermediate Member
Username: Sg569
Post Number: 223
Registered: 12-2004
| | Posted on Saturday, August 27, 2005 - 2:25 pm: |
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Pat00,
When "volting the final" so far the best that I can do is get the dk to 10w and it will not come down at all. Since I refuse to talk on it like that I undid that mod. I just wish that I could get that mod to work. Any Ideas??? |
Patzerozero
Senior Member
Username: Patzerozero
Post Number: 1317
Registered: 7-2004
| | Posted on Saturday, August 27, 2005 - 5:53 pm: |
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ok Sg569-you UNDID the mod, put it back to stock-completely? including putting the limiter/tr24 back to stock? step 2 i listed above is unimportant at this point-whether you undid resistor changes or not. does vr10 vary your dead key NOW? depending on wattmeter you are using, it SHOULD vary from 0 to 4 or 5 watts dead key. (swing should be SLIGHTLY noticeable RMS/avg, maybe up to 7 or 8 watts PEP when UNMODDED)if vr10 will NOT adjust carrier,check it with ohmmeter to make sure it is good. now, assuming radio is working as STOCK, take an Xacto knife & CAREFULLY cut the trace just before tr24-power up radio NOW & you should see 6-7 watts swing RMS/avg or maybe 11 or 12 PEP-because you just 'clipped the limiter'. you are just 'checking' to see the difference, & confirm that radio is working properly. you SHOULD add that 1.5k resistor across the cut you made, to help reduce bleedover, but you can ALSO put it on a switch, so limiter is totally out of circuit for DX/long distance AM. with the 1.5k resistor in place, swing should drop a watt or 2. DEAD KEY should NOT change. steps 4 & 5 are the NPC part of the mod, & again should NOT affect dead key, nor should it change swing-much if at all. but the AUDIO should begin to 'tighten up'/get louder due to compression of negative audio peaks. (as i told kid vicious, experimenting with that 10uf electrolytic cap will change the amount of compression, but that's the best place to start).
at this point, the radio is useable modded as it is, & if vr10 is 'good', & cuts & solders were done in right places, radio should be just fine.
continuing on to the 'volting the final' part, this is where bigger swing increase comes in. you are in effect increasing voltage to the final transistor approx 60% (therefore, swing should increase 60% from where it was after NPC portion completed. if you saw 11 watts swing before, after doing steps 6-10, you should see in the ballpark of 18 watts.)ALL WATTAGES ARE 'BALLPARK ESTIMATES, DEPENDING ON YOUR WATTMETER TYPE/ACCURACY, ETC! the 2sc1969 is LOW VOLTED at around 8 volts from factory to satisfy FCC requirements assuring 4 watts legal max from radio, however manufacturer rates 1969 voltage handling capability to 16 volts(into infinite SWR, so theoretically, you could volt the final, key mic with NO antenna & 2sc1969 will live forever!), & 16 watts output @ 12 volts. (hence the 18 watt output @ 13.8 volts after 'volting the final mod is done). for details see-http://www.cpcares.com/pdf/2SC1969.PDF
if steps 8 & 9 are done in the right place & completed correctly, going back to reset dead key to 2-3 watts should give you 12 watts swing RMS/avg or 18 watts PEP.
the only reason for these mods to NOT work, are installation in the WRONG spot, or something else is wrong with the radio. you are in reality NOT overstressing anything more then the manufacturer of the devices recommends & an early demise of any of the parts affected by the mods is coincidental.
i can't even guess how many times i've done these mods, maybe 100, maybe more? sure, i've messed up from rushing through 'em or not double checking my work, & i've broken the cheap crappy plastic VR pots in the china-built radios, but EVERY SINGLE TIME the mods have worked.
just go SLOW, step by step, & make sure you check that vr10 pot is working.GOOD LUCK!
if that fails  |
Kid_vicious
Advanced Member
Username: Kid_vicious
Post Number: 539
Registered: 9-2004
| | Posted on Saturday, August 27, 2005 - 10:37 pm: |
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sg569, are you sure you jumpered out R196?
if you did not, you will not be able to turn down the dead key enough after volting the final.
when i did the mod; i checked the radio before jumpering R196 out and the lowest i could set the dead key was 6 watts. (i think your wattmeter is a bit too forgiving)
if you did this step and it still didnt work, i like pat's suggestion about checking VR10.
also, i ran my power for the final to the positive terminal of the big cap (1000uf) right near the audio IC (IC6). in my 2000gtl i increased the value to 3300uf.
i like this spot for its nice clean just filtered power.
this mod worked great for me.
BTW, pat, i just did the channel mod to the 2000 on friday. if worked great! i only had to readjust the VCO coil a hair! power does drop off a bit near 27.7 but i doubt i'll ever be using these channels.
do you know of any tricks to broadband the TX mixer stages?
matt
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Patzerozero
Senior Member
Username: Patzerozero
Post Number: 1325
Registered: 7-2004
| | Posted on Sunday, August 28, 2005 - 12:43 am: |
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why certainly, kid!
remove R206(should be 270k resistor)
take a 33k 1/2 watt resistor & a 2.2k 1/2 watt resistor & PARALLEL them TOGETHER in the spot vacated by r206.
power output should now be closer on higher freqs to what it is around channel 10.... |
Jellybean
Member
Username: Jellybean
Post Number: 83
Registered: 1-2002
| | Posted on Sunday, August 28, 2005 - 8:43 am: |
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I have to admit a real goof on one of mine. On an LT
I tried volting as per instructions off the old XL site. Everything seemed to work fine except my squelch no longer functions on am or ssb. Also on ssb the s meter reads a constant 9 and has some noise in it. Am is just fine and meter operates normally. I checked and rechecked and everything looked good. I finally unhooked the volting process, but the problems are still there, so it must have taked a few things out. I haven't really had the desire to look deeper to see if I can find what happened yet.
Anyone else experience anything like this?
Btw... the radio works and operates properly other than those thing mentioned. |
Patzerozero
Senior Member
Username: Patzerozero
Post Number: 1328
Registered: 7-2004
| | Posted on Sunday, August 28, 2005 - 10:52 am: |
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done quite a few LT's & i've flubbed a few times, too, but that is 1 that i never saw before. all mods work just as on XL, 2000 & the rest. wonder if it has something to do with that 'dynamic squelch control' thingie, whatever that may be!(just like cobra soundtracker, another gimmick that's not what it's cracked up to be probably).
it really sounds as though it could be 2 separate problems-the squelch itself & the SSB xmit. i would try to isolate 1 problem, such as the SSB xmit 1st, & go over all adjustments & recheck solder & mod points & all around for bridges, bad connections, out of adjustment, bad parts, etc. |
Sg569
Intermediate Member
Username: Sg569
Post Number: 224
Registered: 12-2004
| | Posted on Sunday, August 28, 2005 - 11:54 am: |
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Pat00,
When I said that I undid that mod I undid steps #7-8 that's all. I left the jumpers, resistors, and caps. Right now Vr10 does allow me to turn down the dk; Radio dk at 1w and swings to about 5w. the highest that I can get the dk right now is 5w(w/ vr10)and then there is no swing on my meter(rat shak). However when I solder that wire (as in steps #7-8) I can't lower the dk from 10w. I'll go back and check my work again.
Kv, My meter is very cheap(given to me, rat shak)and has had a very hard life(can you say rode hard and put away wet?)it has been droped, kicked, thrown, sat on; and more. I have checked it against other meters( ones that have lived a "kind" life and mine still matches those for swr and pwr.) I can't complain too much can I?
Thanks guys I'll try again.
sg569 |
Patzerozero
Senior Member
Username: Patzerozero
Post Number: 1334
Registered: 7-2004
| | Posted on Sunday, August 28, 2005 - 1:41 pm: |
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accuracy of the meter is not important in this case, you want it to show the ups & downs at least!
i would recheck steps 1-5 just to make sure everything is in the right place, even check resistors with an ohmmeter, i ALWAYS do anyway, just to make sure what i thought i grabbed is what i really want.
forget the rat shack meter for the moment. look at radios rf meter. does IT show full scale deflection when vr10 is set lowest & then modulated? when you set vr10 ALMOST all the way UP, does radio rf meter peg to the right, or only go 1/2 to 2/3 of the way? then when you talk, does it peg to the right & show the same HARD swings as the low key? that's just to see if the radio shack meter is working.
are you sure you removed the correct resistor r196, or is it possible you saw that # & pulled the one next to it?
have you talked to anyone or heard it yourself, with the 1st half of the mod? like set key around 2 watts, does it still swing 5, & how does it sound? without knowing if radio shack meter is working, my guess is still something in wrong place or wrong resistor value.
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Sg569
Intermediate Member
Username: Sg569
Post Number: 225
Registered: 12-2004
| | Posted on Sunday, August 28, 2005 - 2:36 pm: |
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Pat00,
Ok Tr24 is resistored, I just fin dbl checking that and r196 is jumped. I will double check the resistor values for the rest of the mod. Tr24 resistor is 1477Ohm( I know not the true 1.5k but close).
To double check pin #9 of IC6 that one is almost the last pin of the chip (with the knobs facing me) I counted 10 pins total. Correct? I just want to double check this.
Thanks Pat00
sg569/ Walter |
Sg569
Intermediate Member
Username: Sg569
Post Number: 226
Registered: 12-2004
| | Posted on Sunday, August 28, 2005 - 3:34 pm: |
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BTW Pat,
The board # in my Xl is PB-208AD.
just though that you would like to know. |
Sg569
Intermediate Member
Username: Sg569
Post Number: 228
Registered: 12-2004
| | Posted on Sunday, August 28, 2005 - 3:07 pm: |
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Hey Pat00,
I just found this one what do you think ????
Highlander1588
Posted on Tuesday, December 25, 2001 - 8:26 am:
--------------------------------------------------------------------------------
The heavy swing mod for the grant and 148 is to turn the radio over and on the PC or trace side locate TP7 and TP8. Then when you find them cut the trace to separate the 2, run a supply wire from a 13.8 volt source to tp 7. You may have to replace R196 with a 1.2K resistor to get your dead key down to 2w`s, I don`t recommend going over 4w`s, you may shorten the life of the final. If you do this with the NPC-RC mod I posted you will have a killer little radio.
Highlander1588 |
Sg569
Intermediate Member
Username: Sg569
Post Number: 230
Registered: 12-2004
| | Posted on Wednesday, August 31, 2005 - 6:03 pm: |
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Ok I'll look for that indent, maybe I hit the wrong pin. That might be my whole problem.
sg569 |
Kid_vicious
Advanced Member
Username: Kid_vicious
Post Number: 552
Registered: 9-2004
| | Posted on Wednesday, August 31, 2005 - 6:48 pm: |
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you bet pat, that cap in my 2000 is 3300uf at 35volts.
thanks for the TX mods, i have already done that one though. the value i used was 39k.
i also removed C207 which is right near R206.
i think the power output will be ok, now im thinking that broadbanding the recieve a bit might be cool. i dont want to increase the channel bleedover too much though.
i have a 148gtl (just acquired) that i want to use as a parts radio for the 2000. i want to add the crystal filter from the 148 to the one in the 2000. ever heard of doing this? any advice?
sg569, you are correct that pin 9 is close to the rear of the radio. the notch for pin one is closest to the front.
when you put the cap on, try putting it on the R194/D36/R228 junction. it can be very confusing doing so much work on a crowded part of the board.
i always use a bright flashlight to make sure im in the right spot.
im still thinking of other possibilities as to why your DK wont come down. HMMMMMMM.
hope this helps,
matt |
Sg569
Intermediate Member
Username: Sg569
Post Number: 231
Registered: 12-2004
| | Posted on Thursday, September 01, 2005 - 5:52 pm: |
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KV,
Thanks, I'll leave thjat end alone and double check the other end.
sg569
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Patzerozero
Senior Member
Username: Patzerozero
Post Number: 1360
Registered: 7-2004
| | Posted on Friday, September 02, 2005 - 6:37 pm: |
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how about a channel guard, kid? when dx stations on channel 6 are pegging my meter @ 30db over S9, or my local is running his suburban w/2 4cx15000 tubes @ 25KW i still get bleedover, but it does cut down quite a bit, when used in conjunction with 2sc2999 & other mods-WOW! did those mods with CG to an LT i sold to a local extra class ham-his 1st CB ever, & he was AMAZED at the receive in a $150 radio. it compared to some of his HF gear |
Kid_vicious
Advanced Member
Username: Kid_vicious
Post Number: 560
Registered: 9-2004
| | Posted on Saturday, September 03, 2005 - 11:22 pm: |
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yeah, i know i need one, i just like to try things. seems like a waste not to use this little 148 for something. its a junker aside from a good PLL (already pulled and put in 2000)
good driver and final, good filter (FT3), and just misc. junk. radio is just too torn up to be of good use. (too many cuts in pc traces etc...)
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Patzerozero
Senior Member
Username: Patzerozero
Post Number: 1386
Registered: 7-2004
| | Posted on Sunday, September 04, 2005 - 1:58 pm: |
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hmmmmm. yanked channel guard out of my XL this morn, then put it back in & yanked 2sc2999. rcv went 'scratchy' after a BAD set of plugs & wires drove next to me at traffic lite. this THING was causing all kinds of popping & rfi, & after he drove away, rcv sounded 'odd'. thought audio ic went, you know the sound, but xmit was perfect, & told son to jump on base & he sounded fine as well. hmmm hmmm hmmm. popping remained as if anl/nb circuit went out, & noise just seemed to be increased, got closer to home, had son crank icom & i went to adjacent channels & even bleedover sounded odd/fuzzy. yanked channel guard & it didn't seem to make any difference. replaced 2999 with a proper 1674. everything sounded good. put channel guard back in, things are still good. wonder what happened with 2999? no more time today, will have to put another 2999 in & see if things go back to as they were.
my xmit is unaffected, though
talked to 100 in bermuda on ch 6. he said it sounded good . too bad there was NO dx AT ALL during net |
Kid_vicious
Advanced Member
Username: Kid_vicious
Post Number: 568
Registered: 9-2004
| | Posted on Sunday, September 04, 2005 - 10:23 pm: |
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that is strange. was it a VW thing?
are you saying that you were runningthe radio for a while with NOTHING in the TR14 spot?
maybe i just misunderstood.
im stumped.
have you ever noticed that the NTE cross referrence for the 2sc2999 is the NTE107 and that the cross referrence for the 2sc1674 is also the NTE107? have you aver tried putting an NTE107 in the ssb detector? (TR19) instead of the 1674?
just a thought.
one more question since on one seems to be listening but us. i just bought a BK presision 1805 freq. counter. this is my first "real" counter. (no so-239's)
my question is what kind of probe do i need for the BNC connector on the front and where can i find one?
thanks in advance,
matt |
Patzerozero
Senior Member
Username: Patzerozero
Post Number: 1392
Registered: 7-2004
| | Posted on Sunday, September 04, 2005 - 11:08 pm: |
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more hmmmmm's. didn't check SSB. was like NB/ANL was switched off. couldn't hear a thing-AM was perfect. channel guard was in for months & working fine, so i know it was in right. took CG out AGAIN, & checked SSB-FINE. put 2999 back in-still good. tried CG again-AM fine SSB-still like nb/anl disabled. put another CG in, worked fine AM/SSB for a while, then SSB 'popped' again. nb/anl switched off on AM & engine noise comes in, flipped on & noise disappears. SSB, switching nb/anl is like NOT working. CG back out, cap back in & everythings fine. (quadruple checked connections, even reversed 'em-that made it worse. so i know it's wired the way it was-correctly). also checked & replaced d1,2,21,22 schottky mod-no difference on SSB. AM fine.
oh well, no CG. what's a little bleedover? XMIT works though |
Sg569
Intermediate Member
Username: Sg569
Post Number: 243
Registered: 12-2004
| | Posted on Wednesday, September 21, 2005 - 10:47 am: |
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Pat00,
What would happen if Q37 and Q39 were to go south?? Would I lose pwr output??
Thanks
sg569 |
Patzerozero
Senior Member
Username: Patzerozero
Post Number: 1522
Registered: 7-2004
| | Posted on Friday, September 23, 2005 - 6:49 pm: |
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q39 is the predrive to the 2166 or 1306 driver, & q37 is the bias to the 1969 final. it is more likely that either the driver or final or both are what went south. yes, either would show a MAJOR decrease in output, both would show NO output, AM or SSB.
somewhere you are doing something to the wrong part. either applying voltage to a place that does not like having voltage applied, or applying TOO much voltage.
wife is rushing me along here, so i don't have time to read all the way thru again, but, IC6 wrong pin...i don't know, but the only thing that any mistakes to these mods could cause the finals to pop, would be voltage, & that's probably the ic6 part. unless you just flat out mistook something for something else...
i'll try to go thru this again over the weekend for ya |
Sg569
Intermediate Member
Username: Sg569
Post Number: 247
Registered: 12-2004
| | Posted on Sunday, September 25, 2005 - 2:42 pm: |
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I DID IT AGAIN. I SMOKED MY XL. No audio over am, ssb, or pa functions. I will be checking the caps listed above. I did notice on Sun. that she was not swinging much at all on ssb( about 3w total on ssb- me no likey). Right now when I key the mic the meter drops to 0 and that is all. Receive is good. But that is it.
Thanks sg569 |
Sg569
Intermediate Member
Username: Sg569
Post Number: 261
Registered: 12-2004
| | Posted on Wednesday, September 28, 2005 - 12:25 pm: |
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Still no out put, changed all the caps; NO output.
I'll check Q37+Q39 maybe I smoked both.
Thanks
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Sg569
Intermediate Member
Username: Sg569
Post Number: 263
Registered: 12-2004
| | Posted on Wednesday, October 05, 2005 - 8:08 pm: |
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Pat00,
I have since replaced the sc2166 and sc1696. Still nothing. I replaced Caps c18, c153, c186, and c95; got P/a function again, but no xmit(still).
Thanks for the help,
sg569 |
Patzerozero
Senior Member
Username: Patzerozero
Post Number: 1624
Registered: 7-2004
| | Posted on Saturday, October 08, 2005 - 4:17 pm: |
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i sent you an e-mail a while back about the IC6, walter...as for what's wrong at this point, you may wanna start fresh by seeing if there's a tech in your area willing to check it out & get ya back up & running...
sorry, but sometimes it's hard to troubleshoot without actually 'seeing' things as they happen |
Sg569
Intermediate Member
Username: Sg569
Post Number: 265
Registered: 12-2004
| | Posted on Sunday, October 09, 2005 - 2:25 pm: |
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I understand that. Easier to diagnose the engine prob. when the car is in front of you instead of over the phone. Thanks for the help and advise.
sg569 |
Outkast
Junior Member
Username: Outkast
Post Number: 20
Registered: 9-2005
| | Posted on Tuesday, October 11, 2005 - 2:23 am: |
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Hey guys I have been thinking of doing some of the mods listed above and the only thing I cannot seem to find for the life of me is the R-131!!!!!!! Where the heck is it? Looked for a good hour or two and came out empty handed! |
Sg569
Intermediate Member
Username: Sg569
Post Number: 266
Registered: 12-2004
| | Posted on Wednesday, October 12, 2005 - 12:16 pm: |
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Ok, W/ the knobs facing you, find L2, once you find L2 look just below L2; You should find R131 there w/Q26
Hope this helps
sg569 |
