Uniden PC78 Elite

[thetnhillbilly]

I posted this on different forum, but am hoping to get more help here.
I read the mods at http://www.dtbradio.com/tips but I guess i need things dumbed down for me, because I don't know the lingo and am not very technical. Is this the best mod? It says to do the same as the cobra 29 with the exception of removing capacitors. I see where it says to add capacitors, but not remove them. Do I do exactly as I says for the 29? If not, what specifically do I omit? If you could rewrite it with only what I need for the pc78, that would be ideal. Also, being new I have trouble with the language. When it says "solder a jumper across" doesn't that create a short across that part of the circuit? Do I replace the part with the jumper, or add the jumper to it? Same question regarding the caps. Finally, when not specified, do I use carbon film resistors and dipped silver mica capacitors? I'm really sorry if these are just really simple questions to you and waste your time, but if I decide to try this I want to do it right.

 

[Carl]

dtb should be around to awnser this sometime.

 

[bushwacker]

For the part of the mod where you adding a jumper, you need a connect6ion there because you are removing something. Like I think your refering to D8 (anti spiking diode), you completely remove the diode and then put a jumper across where the diode was.
The mod will work fine, and your radio is identical to the cobra 29. Nothing is different. There are a few other thing to do, but you get to the point where the added mods and time don't gain alot of watts and makes the radio run "dirtier".
If you follow those instruction the radio will put out some decent power.
All the compnents will be labeled on the board-- D8 would be diode 8-- L14 would be coil 14 (L stands for inductance, a coil of wire of somesort), TR or Q stands for transistor.
If its the best mod for the radio, I'm not sure. It depends on what you mean by best. If you mean good ouput power without having to hack the radio apart then yes.
You can get more extreme with power modifications.But this isn't for you or someone new.
The part of the mod that makes the big difference is the 1969 transistor. Soldering small value caps across C62 will increase carrier power... c59 also
What I will usually do is change the driver as well as the final. For the driver I will put in a 2314 transistor, something you might want to keep in mind while your hunting around for mods.

If this is your first mod,,, just stick with the instructions at DTB. They will work fine. If you want to see what else is available, search around for cobra 29 mods. You will see alot of different things that guys do.
Your radio and the cobra 29 are the exact same. Your good to go if youy follow the instructions at DTB

 

[Butcher318]

Bushwacker, good post. The uniden 78Elite is an exellent radio with just a proper tune and alignment. DTB knows his stuff so get with him and I'm sure he can help. Alot of people swap in a 1969 final and do nothing else, they end up with no increase in power because they did not change the driver and never re-tuned the radio.

 

[DTB Radio]

I've been moving away from the 1969 lately due to availability. I've been using the ERF2030 final, using the basic mods listed on the cbtricks.com website, with 2 exceptions. I increase the cap going from the driver to the final to about 150pf, and the cap that goes to ground after the final to 100pf. Other than that, I follow whats on cb tricks.

As for the 1969 mod, part numbers are the same as the Cobra 29 part numbers.

 

[thetnhillbilly]

Thanks to everyone for the advice. You have all been very patient with me and again, thanks.

 

[smalltiredart]

:guitar

 

[4play]

Justin did my PC78 & it made a huge difference.
Nice radio.

 

[Master Chief]

I guess i need things dumbed down for me, because I don't know the lingo and am not very technical.

I would HIGHLY recommend letting a professional do the work then. Unless of course you have a spare radio you don't mind possibly destroying. I'm not saying not to experiment, that is half the fun, but if you want it done right, you should seek out a pro. They have the experience and TOOLS to do the job right. If you don't know what you are doing, you could end up with a parts radio with a few bad parts in it. Good luck on yur project!