Radioactive Wack Pack Unveiled

[Geekster]

Galaxy 88 / 99 modification.

Here we go, C187 and C235 go to a .2 monolythic, the input coupleing capacitor goes to a 2.2uf tamtalum, and the low end "rolloff" capacitor goes to a 4.7uf tantalum. R187 to 10K. R 235 to 10K, this improves AM modulation depth.(this increases the highs and the lows) Remove incorrect bypass capacitors on several version of the echo boards. (sorry, do not have component values off hand, I go off memory, but typically there are about anywhere from 2 to 4 depending upon the echo board version. They are incorrect values, and roll off the highs and lows too soon.

Add .047 mylar across speaker terminals as RF bypass. Add .047 from left side front screw trace to circuit board ground by mic amp as RF bypass.

Change 820pf capacitor to metal mica near finals, change 560pf and 68pf (by finals) to 680pf silver mica.

Remove J30 add 250pf silver mica capacitor. (this blocks DC, but passes R.F. in this circuit just fine) Looking at where J30 was, on the side AWAY from the 1st R.F. amp, solder side up (to the left) add two 1N4148 diodes back to back, in other words, one in one direction, and another in the other direction. This provides clamping for receive, should a strong station get too close. (prevents damage to the front end)

From middle pin of the 2SB754, take a piece of teflon wire, and run it from where the final connects to the mirror board on the solder side to the 2SB754 solder side. This make up for any voltage drop. (several small jumpers supply VCC to the final output section.)

Next increase the gain of the TX mixer, by removing the 1K ohm resistor fron pin 12 to ground, and adding a 270 ohm resistor from pin 12 to ground (pin14). Don't go below 270 ohms. Remove C235.

Add about 68pf to 100pf across the driver to final transistor coupling capacitor.

Align the TX bandpass filters.

You should see 50 watts EASY on a Bird 43P @ 14.1 volts supplied to the radio.

There are of course more things that we do than just this, but this is the basic modification.

Maybe next month we'll get into changing the 1st R.F. amp to a dual gate mosfet, and the mixer to a dual gate mosfet, and how to control the gain.

Hmmm :?

 

[dxhound]

I look at what justin and others do to peak up radios and wonder why. How much does this cost in labor and parts to your customer? Why go through all that trouble to achieve an extra 5 watts. Im sure if you are involved in this post you are familiar with the laws of bell and know that 5 watts will amount to nothing in the end when considering 45 watts already. On a completely stock dual final radio using bipolar transistors, and leaving the limiter intact, there is no reason 43 to 45 watts should not be obtainable on 14.1 volts. Now with that said the only time I make modifications are when someone brings me a radio with a blown driver or final bipolar transistor. In this case I replace them with either the erf 2030 or Irf 520's and make necessary changes to the bias circuit. The reason I make these changes is because for only a few more dollars the radio now has all new driver and final amps and when the customer has problems down the road, the cost to replace these mosfets is far less than said bipolars. Not to mention they are more efficient and do offer a marginal to fair increase in avg and pkpk talk power.

Im not asking people to post what they charge for parts and labor to act as an advertising ploy , but rather to weigh the cost vs benefit. As for me I usually charge $25 to retune most radios
(cheaper on 29, 25, 66 etc) and $55 to do the mosfet swap on dual final chassis (or single to dual modification) and $45 to modify single final chassis. Obviously prices do very with situations but these are good ballpark figures. I usually dont recommend spending the money on mosfets unless there is something wrong with the standard bipolars.

I hope by using names I didnt upset anyone. I just tried to use a name that was allready associated with this post rather than drag someone new into it. So Justin please dont be angry, Im not attacking you in any way and if there is a problem I will modify my post.

Lets not make this a money war. Prices will vary due to location, and for god sake No name calling!

 

[Butcher318]

dxhound, nothing wrong with what you do there for $25 dollars at all. I do have to say though, I have been hard on justin from time to time, when you look at what he detailed there that is a pretty fair amount of work to do to a radio. That would be well worth 50-60 dollars, there is more there then just 5 watts. And DTB is on top of things as always too.

 

[dxhound]

I agree, That is alot of work for $50-$60. However is it nessary?
All that work only shows 50 watts on a bird peak meter. A properly tuned dual final (bipolars) radio will show 40-45 watts at 14.1v and using mosfets, I have seen in upwards of 60 watts. Dont get me wrong, some people want that extra 5 watts to help push linears but when comparing price to benefit I just dont see it. But again I am just throwing out opinions. One of the neatest mods I have seen involves "stacking" mosfets. The demo radio shown was producing a clean 90 watts with a 22 watt carrier.

 

[Geekster]

I look at what justin and others do to peak up radios and wonder why. How much does this cost in labor and parts to your customer? Why go through all that trouble to achieve an extra 5 watts. Im sure if you are involved in this post you are familiar with the laws of bell and know that 5 watts will amount to nothing in the end when considering 45 watts already. On a completely stock dual final radio using bipolar transistors, and leaving the limiter intact, there is no reason 43 to 45 watts should not be obtainable on 14.1 volts. Now with that said the only time I make modifications are when someone brings me a radio with a blown driver or final bipolar transistor. In this case I replace them with either the erf 2030 or Irf 520's and make necessary changes to the bias circuit. The reason I make these changes is because for only a few more dollars the radio now has all new driver and final amps and when the customer has problems down the road, the cost to replace these mosfets is far less than said bipolars. Not to mention they are more efficient and do offer a marginal to fair increase in avg and pkpk talk power.

Im not asking people to post what they charge for parts and labor to act as an advertising ploy , but rather to weigh the cost vs benefit. As for me I usually charge $25 to retune most radios
(cheaper on 29, 25, 66 etc) and $55 to do the mosfet swap on dual final chassis (or single to dual modification) and $45 to modify single final chassis. Obviously prices do very with situations but these are good ballpark figures. I usually dont recommend spending the money on mosfets unless there is something wrong with the standard bipolars.

I hope by using names I didnt upset anyone. I just tried to use a name that was allready associated with this post rather than drag someone new into it. So Justin please dont be angry, Im not attacking you in any way and if there is a problem I will modify my post.

Lets not make this a money war. Prices will vary due to location, and for god sake No name calling!

Well said

 

[Moleculo]

If you look more carefully at Justin's mod, it's not just to get a few extra watts. He is changing the audio characteristics and frequency response. He's also changing some RF bypass caps which he says are incorrect values stock. The back to back diodes act as strong signal protection to protect the front end (a nifty thing to have in a truck stop).

None of these changes have anything directly to do with getting "more watts". Is it worth it to you to spend the money to do all this? That's up to you to decide.

 

[TWH1968]

Hmmm :?

Could someone explain where to connect the two diodes mentioned in the clamping mod?

 

[julthree]

super wack pack

no only is it bull. dave is a low life. i had him super whack pack and do a so called super receive on a general lee which was horrible when they finished the radio. the radio went back and fourth to his shop or what ever it is its a p.o. box four times. after a hundred dollars in shipping that i payed for dave told me they cant find any thing wrong with the radio ??? every one said my 29 out talked it. we put it on the meter a whole 21 watts well after six calls to dave he agreed to refund my money less shipping. ok take the loss i told my self he emailed the r.m.a. number . after a bout two weeks no credit to my pay pal so i filed a claim. took a month to get my money back. pay pal dealt with dave. i also ordered THE PUNISHER antenna i called him told him you have the radio i dont need the antenna. no problem he said three weeks later no credit called amex received my money back from amex. they would investigate . pice shit DAVID i wish he was close to me he wouldn't be ripping people off ???

 

[GLR]

Who the hell is David?

 

[pro151]

Who the hell is David?

That's what I was wondering.

 

[julthree]

dave super wacky pack

mr. radioactive radios

 

[GLR]

mr. radioactive radios

His name is Michael Kersnowski.

 

[BOOTY MONSTER]

Michael Kersnowski - Google Search

 

[julthree]

sorry

sorry it has been at least seven months since i had that trouble with him

 

[DTB Radio]

Hard to believe this thread is still active after more than 4 years.