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Therealporkchop
Intermediate Member
Username: Therealporkchop
Post Number: 202
Registered: 11-2002
| | Posted on Saturday, June 04, 2005 - 1:18 am: | 
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Everyone here knows about the 1N4001 or 1N914 diode and resistor mod for the Galaxy radios. But isn't there a better way to achieve the results without doing this? Anyone that has ever done this and looked at it on a scope knows what it does to the modulation signal. You see the peaks flat-top and the minute audio drop outs that happen.
So, is there a better way to mod this radio? And why do some radios sound so big and strong and other radios just like it and modded like it don't sound so BIG? This, I've ask 1 million times, so here is 1 million 1. |
Patzerozero
Advanced Member
Username: Patzerozero
Post Number: 858
Registered: 7-2004
| | Posted on Saturday, June 04, 2005 - 11:11 am: |
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"...a way of lowering the carrier level of a unit while maintaining all of the PEP swing of the audio.
almost every AM unit has an antispiking diode on the output of the audio transformer. this is where the DC is fed to the driver and final. the reason it is there is to prevent the RF positive spikes from exceeding the insulation factor of the audio transformer, causing shorting between the primary and secondary. this diode is generally a 1 amp 600v PRV. this is about the same as most of the reverse polarity protection diodes.
silicone diodes require about .7 forward voltage to begin conduction. this means, if we put 2 such diodes in series, it would require about 1.4 volts to start conduction, 3 diodes 2.1 volts, etc.
as you lower the voltage on the and final of a unit, your wattage output on dead key will drop. the audio swing in this case will NOT drop because the diodes are forward biased. all positive swing will continue through unchanged(this is where the NPC-RC & volting the final mods come into play & really get your audio cookin').
lift the cathode of the antispiking diode and add as many diodes as required to obtain the correct dead key. using a switch can give different levels of carrier".-as taken somewhere from 'cb tricks'
now, that is the preferred method of lowering the carrier & maintaining swing. all other standard mods are required, such as peaking & adjusting AMC/ALC, AM power, etc. also, NPC-RC & volting final should be done, if wanted, prior to diode mod. & the infamous clipping of the limiter & PUTTING IT ON A SWITCH should also be done beforehand.
believe it or not, though clipping the limiter increases succeptibility to bleedover it will give you that 'BIG' sound. it's just when ALL knobs, pots, adjustments are cranked WIDE OPEN, that even the BEST can sound like crap.
i've said before, PICK UP A USED RADIO FOR EXPERIMENTATION PURPOSES. a cobra 29/uniden 76/78 or a 148/XL type, if you should ever locate 1 CHEAP, in good, unmodded condition-GRAB IT!!! you can then find out how willing you may be to take a soldering iron to a $400 radio, & when you should stop. & you can try all the mods you hear about, see how they work & which ones you like or don't.
keep in mind, many mods affect the AM portion of the radio in a 'good' way, yet can make SSB sound cruddy. galaxy is an example. cranking the AM WIDE open in many cases gives the dreaded SSB wobble. again, get that 'guinea-pig' radio & see how to get it where it sounds good to you. |
2600
Advanced Member
Username: 2600
Post Number: 569
Registered: 7-2002
| | Posted on Saturday, June 04, 2005 - 12:00 pm: |
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There is so much misinformation out there on this subject, it's mind-boggling.
I mostly leave the subject completely alone on this forum and the dozen others where I lurk. Too much noise, hard to get a 'signal' through all of it.
I don't discuss the exact combination that we use, just because it will get lost in all the "noise level" of DISinformation that's out there.
Besides, there is an almost spiritual devotion some folks have for one mod or another, TOTALLY unrelated to either the SOUND or the engineering behind it.
What I advise is to listen to the radios you hear. When you hear one that sounds good to YOU, ask where it was 'set up'.
Then take the same model radio to the same guy and have it set up that way. This is how we arrived at the setup we use for one model or another, by paying attention to what people ask for. Never mind what I think it sounds like. Not everybody has the same notion of what sounds good TO THEM.
73
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Patzerozero
Advanced Member
Username: Patzerozero
Post Number: 865
Registered: 7-2004
| | Posted on Saturday, June 04, 2005 - 1:50 pm: |
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'i've said before, PICK UP A USED RADIO FOR EXPERIMENTATION PURPOSES. a cobra 29/uniden 76/78 or a 148/XL type, if you should ever locate 1 CHEAP, in good, unmodded condition-GRAB IT!!! you can then find out how willing you may be to take a soldering iron to a $400 radio, & when you should stop. & you can try all the mods you hear about, see how they work & which ones you like or don't.'
porkchop requested a better way to do it. i never said that was a better way, but a slightly different way, & i just quoted from a 'repected' source, giving them due credit. MY way to modify 148/XL/TR296 is posted elsewhere on this forum & does not neccessarily use the above quoted method. i neither use nor have any desire to modify a galaxy radio for my own & am 100% satisfied with the sound quality & positive reports regarding my own heavily modded grant XL, magnum delta force, S9, AR3500, IC735 & rci5054dx100. that is why i requoted my 1st paragraph for the umpteenth time-'find what mods YOU like'.
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Hollowpoint445
Intermediate Member
Username: Hollowpoint445
Post Number: 351
Registered: 6-2004
| | Posted on Saturday, June 04, 2005 - 8:58 pm: |
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2600 - I don't think most people really care how they sound, they just want to be loud. Really loud.
Most of these mods are rehashed from early amateur AM tube equipment that wasn't up to the demand of a high constant carrier so they developed ways to get the most they could out of the equipment they could afford. They've simply been adapted to solid state.
What most people don't realize is while these techniques increased the peak power levels that the equipment could handle, the signals were less than pleasing to the ear and when less expensive equipment came out they upgraded quickly and never looked back. |
Bc910
Advanced Member
Username: Bc910
Post Number: 527
Registered: 7-2004
| | Posted on Saturday, June 04, 2005 - 9:46 pm: |
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Hey Pat what mods have you done to the S9 now any way (if any)?
BC |
Tech808
Moderator
Username: Tech808
Post Number: 5973
Registered: 8-2002
| | Posted on Saturday, June 04, 2005 - 9:52 pm: |
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Bc,
I am not sure what he has done to it but it SOUNDS GOOD!
He is slamming in here now on 13 / 27.115 ~ AM & LSB and talking to everyone here in Central Il.
Lon
Tech808
CEF808
N9OSN |
Patzerozero
Advanced Member
Username: Patzerozero
Post Number: 870
Registered: 7-2004
| | Posted on Saturday, June 04, 2005 - 10:49 pm: |
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44's & early sunday AM sporting events required the shutting down of my station. phooey!
even though radios are in basement, they hear the noise & would rather be playing then sleeping...& the wife would be yelling & i wouldn't be having fun!
THANKS LON!!! you were S-9+ on SSB, & 20-30 db over S9 on AM on the icom, on the S9 you were banging the needle at 40 over!
i actually keyed up BOTH my S9 & my ic735 on AM & SSB. wanted to get delta &/or 3500 in there too, but soldering iron was hot...the icom was 40-60w on SSB & about 20-25w on AM, the S9 was 35-40+w on SSB & FULL power AM, 12w key/35 to 40+w swing. icom had stock mic, S9 had an old black road devil i just wired up for someone. AM high power pot & ALC were both tweaked a while back to get into the 40 watt range, wasn't all that close out of the box. (both had black magic marker on them, as well as AM low power, & AM modulation-out of the box...actually, at the time, didn't know what that pot was for, was kinda hard to follow its traces, may go back in again!)i get even BETTER reports then i originally got-especially with rf power knob turned all the way up. 12 watts dead key & 40+ watts swing gets better reports then 1 watt key & 40+ swing. makes sense, though the magnum topgun setup is just about the ONLY radio that can make that ratio sound good. 12 & 40 makes it sound even better! |
Therealporkchop
Intermediate Member
Username: Therealporkchop
Post Number: 205
Registered: 11-2002
| | Posted on Thursday, June 16, 2005 - 1:16 am: |
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Hmmm. Well all my stuff must stink, cause I can't ever hear anybody on 13 AM or LSB. I'm going outside right now and take a hammer to all my junk...
The diode mod I mentioned in the begining, there are two or three ways I've seen this done. On the Galaxy radios, cause I own a few and most of what I work on is Galaxy, lifting up R238 and doing it there works pretty good. I've seen some guys that put them on the solder side over near the 754 transistor. MY experience is the you HAVE to run a low deadkey or it won't modulate correctly if you put on the solder side.
I was actually wondering if there were other tricks instead of this diode mod junk. I don't have top notch equipment, but I use the old B&K stuff, 1040, 2040 and 1801 (I believe that's the freq counter number). A brand new freq counter, and two OLD B&K O'scopes. A 10mhz and 30mhz. Doing those diode mods always shows over modulation on the scope, period.
I was just wondering if there was another or better way to get the power up and the audio louder.
As a matter of fact...forget it. I'm going to buy myself an S9...find the Jesus Christ of S9 tuners...and send it to him...is he at Copper?
Thanks!!! |
Patzerozero
Advanced Member
Username: Patzerozero
Post Number: 943
Registered: 7-2004
| | Posted on Friday, June 17, 2005 - 4:32 pm: |
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S9S9S9S9S9S9S9
replacing an AM galaxy with an S9 is....well you can only imagine. EVEN if someone were to say 'that 50 watt AM galaxy sounds louder ...', that is far from the whole picture. the overall quality of the receive & the quality of your transmitted audio is just so much better on the S9. there really isn't much needed to be done to the S9-the receive on mine IS AWESOME out of the box, & the transmit, which didn't match the hype-at first- was still 1st rate. after locating several internal adjustments, it, well, now exceeds the hype. around 12 watts dead key, variable to 1, & legitimate swing is 40+. audio is top notch-LOUD & crystal clear.
of course, if somebody is just interested in wattage, a $70 tristar 120 & 4cx15000a amp will outalk ANY S9 or galaxy around....
as for ch 13,c'mon porkchop! i NEVER heard anybody on 13 other then sunday net times-yet call EVERY SINGLE TIME DX IS RUNNIN'. managed to get throught to 808 & corncob a couple saturdays ago. they were BOOMIN' in here! |
Bc910
Advanced Member
Username: Bc910
Post Number: 537
Registered: 7-2004
| | Posted on Saturday, June 18, 2005 - 12:06 am: |
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Pat
What's the word on your buddy with the "power house" S9? Has it blown up yet? if not, you need to find out exactly what he did!!! BTW what "adjustments" are you talking about that helped your recieve?
BC |
Patzerozero
Advanced Member
Username: Patzerozero
Post Number: 948
Registered: 7-2004
| | Posted on Saturday, June 18, 2005 - 9:27 am: |
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'the receive on mine IS AWESOME out of the box'-NOTHING has been touched in regards to receive. on my mfj1700c 6 position switch i've compared the S9 to my 2999 modded XL & AR3500, as well as ic735, delta force, 148, TR296 & a host of others-including galaxys & rci's. EXCEPT for the icom on SSB with preamp, the S9 outhears 'em ALL. i've even used the S9 to receive a signal & switched to the higher output of the ar3500 or ic735 to transmit.
as for my transmit, as impressed as i was when i got it, it didn't appear to do full output. after my buddy got his, & looked at mine, we found MINE had black magic marker on several of the pots. 1 was AM high power, & 1 was AMC. by adjusting the 2 together, we got it to key as high as 12 watts & have 40+ watts PEP on over 1mhz of bandwidth. we never located ALC, or low AM power, but since it turned down to almost 1 watt from the front control, we figured it to be satisfactory, and 40+ swing AM & SSB, so we didn't make any other SSB attempts at adjustment. we guessed as to what these pots were by attempting to follow their traces. we didn't touch the others as we weren't sure what was what. i have not been able to get my S9 or XL up to his shop in CT, as it's a 4hour drive each way, over 150 miles, many of it in the backhills of CT, need to make a weekend out of it & just haven't had time.i have spoken to him, via phone as well as radio (over 70 miles) & he seems to be as impressed with my S9 as i am with his-either his 'stock' 1 or the test mule that he keeps blowing up. i discussed 808's postings on S9 mods with him & he has redone his 'stocker' for a bit more out, & continues to play with & blow up the other 1. his attempts at 'volting' the final as well as changing bias & even swapping out for different finals have shown wattage gains, but the end result has been blown finals EVERY SINGLE TIME. 1 mod got 40 watts RMS on bird. OUCH. it lasted only a few keys. the 1969's don't take to volting & abuse like bigger physical-sized transistors such as 2879/2290's do.
his is doing 14 or so key & better then 45 PEP, which is probably the absolute max that's gonna be seen. talking on mine with 10+ watts of key & 40+ watts of swing DOES SOUND DIFFERENT then 1 key/40 swing-it has LOTS more punch. it keys a davemade400(no driver) at over 250 watts & swings to over 900 watts. most of those boxes take closer to 18+ key/100+ swing to get that kind of output.
so, the S9 turns out to meet the hype, & work pretty well with custom amps. as i said since day 1, DEFINITELY A KEEPER!!!
S9S9S9S9S9S9S9S9S9S9S9S9S9S9S9S9S9S9S9S9S |
Bc910
Advanced Member
Username: Bc910
Post Number: 539
Registered: 7-2004
| | Posted on Saturday, June 18, 2005 - 8:15 pm: |
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Pat, it's fathers day and me being a new father and this my first fathers day I thought maybe you might want to send me one of those amps, you know as a fathers day present! HEY I'll even pay the shipping what do you think?
BC |
Patzerozero
Advanced Member
Username: Patzerozero
Post Number: 952
Registered: 7-2004
| | Posted on Saturday, June 18, 2005 - 11:25 pm: |
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i hear the comedy channel has a few openings for 'funny-guys'! bc, send your resume to...
wait a minute here, at this point in your life/marriage, your WIFE should get you WHATEVER you want, of course signing your new baby's name to it. 15 years from now, when you're where i am, you TELL her if she don't get it for you, you'll just spend the rent money on what ever your hobby REQUIRES. & hope she don't kick your butt out the window!
CONGRATULATIONS & ENJOY YOUR 1ST FATHERS DAY! |
Therealporkchop
Intermediate Member
Username: Therealporkchop
Post Number: 206
Registered: 11-2002
| | Posted on Wednesday, June 22, 2005 - 8:14 pm: |
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Well, at this point I'd rather have an S9 than have a Galaxy. Well, rather than have the 48T I have now. I was going to buy myself a DX73 or a DX99, but I think I'd rather have the S9 than have another Galaxy laying around the shack. |
Patzerozero
Advanced Member
Username: Patzerozero
Post Number: 962
Registered: 7-2004
| | Posted on Friday, June 24, 2005 - 8:32 am: |
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hands down, vs either of those 2 galaxys-it's the S9!!! |
Therealporkchop
Intermediate Member
Username: Therealporkchop
Post Number: 207
Registered: 11-2002
| | Posted on Friday, June 24, 2005 - 10:07 pm: |
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I'm going to be real ticked with you and BC if I buy an S9 and it isn't what you've made it out to be...
HAHA..I'm going to beat it into little pieces and mail it to you... |
Bc910
Advanced Member
Username: Bc910
Post Number: 545
Registered: 7-2004
| | Posted on Saturday, June 25, 2005 - 12:20 am: |
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PorkChop!
Dont beat it in to pieces just mail it to me
BC |
Hollowpoint445
Intermediate Member
Username: Hollowpoint445
Post Number: 448
Registered: 6-2004
| | Posted on Saturday, June 25, 2005 - 12:06 pm: |
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That would be so cool. A big envelope of radio pieces - just like a jigsaw puzzle. |
Therealporkchop
Intermediate Member
Username: Therealporkchop
Post Number: 214
Registered: 11-2002
| | Posted on Saturday, June 25, 2005 - 9:04 pm: |
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Ahh...that would be funny as you know what. I'd love to see the look on his face!!
I guess the diode is the only mod available...how sad. |
Patzerozero
Advanced Member
Username: Patzerozero
Post Number: 970
Registered: 7-2004
| | Posted on Sunday, June 26, 2005 - 5:51 pm: |
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Therealporkchop
Intermediate Member
Username: Therealporkchop
Post Number: 218
Registered: 11-2002
| | Posted on Tuesday, June 28, 2005 - 12:14 am: |
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Pat,
You said "lift the cathode of the antispiking diode and add as many diodes as required to obtain the correct dead key". Which diode would that be on the Galaxy radios? And why couldn't you just use the AM Low Pwr Adj to lower the deadkey? Or is doing the diode mod doing the same thing??
There has got to be another way of modding or tuning a Galaxy and some others than the diode at R238. There just has to be.
This statement will cause response for sure...I get at most 12 watts AVG power and 45-50 watts PEP from my Galaxy 77. This is with matched finals and twisting and turning everything I can and hours of tuning and messing in that radio. It's been running everyday for 2 years without one problem. But all my other Galaxy's I get around 10 watts AVG and 40 PEP. I guess this is the MOST you can get from these radios regardless of what you do to them. I AM NOT SAYING THAT THESE FIGURES ARE CORRECT. I am using a crappy meter, but as I've said before, it's close to a Diamond that was calibrated to a Bird. Atleast on the scale I use, I think it's close.
Anybody have any more suggestions?? |
Twowatt
New member
Username: Twowatt
Post Number: 1
Registered: 7-2005
| | Posted on Sunday, July 03, 2005 - 5:09 pm: |
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PorkChop,
In response to your "lift the cathode of the antispiking diode and add as many diodes as required to obtain the correct dead key. Which diode would that be on the Galaxy radios?"
There is not an "antispiking diode" on those Galaxys, because they don't use a modulation transformer. But, on the AM cbs; that mod was from the 70's and was called "Dial-a-Watt". We used a 6 position wafer switch from Lafayette and HEP170 diodes and "dialed" down the dead key to boost our modulation (the swing was not as high with more diodes switched in, but the loss was minimal). P.S. all the mods saying to strap this diode - DON'T DO THAT! regards |
Therealporkchop
Intermediate Member
Username: Therealporkchop
Post Number: 227
Registered: 11-2002
| | Posted on Monday, July 04, 2005 - 5:26 pm: |
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Well, on the Galaxy 10 meter radios, C190. I've learned that this will give some pretty good swing if you change the 100uf 16v to 470uf 16v. I changed this in my 77 and a guy I've been talking to for years on the radio told me that he "liked" the swing my radio had. He didn't know it was the same radio.
I can't wait to get that S9 and see how he likes that. I hope if it stinks, Copper will take it back or BC and Pat are going to get a parts radio. |
Patzerozero
Senior Member
Username: Patzerozero
Post Number: 1003
Registered: 7-2004
| | Posted on Monday, July 04, 2005 - 10:18 pm: |
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