Uniden Pro 510xl

[gr1m]

Hi guys im new to the forum here. I am wondering if there was any way to lower the dead key on my Uniden to use it with my lil amp till i save up to get me a better radio. I dont know what kinda amp it is all i know is it has 2 SD1446s in it, and the uniden is the 1999 version.

Thanks in advance

Aaron

 

[LeapFrog]

Hi guys im new to the forum here. I am wondering if there was any way to lower the dead key on my Uniden to use it with my lil amp till i save up to get me a better radio. I dont know what kinda amp it is all i know is it has 2 SD1446s in it, and the uniden is the 1999 version.

Thanks in advance

Aaron

If you really have to: Add a diode inline (use a 1N4003 or 1N4001 whichever kind that is already present inside your radio) keep the band facing the same direction, you will be adding the diode in series to the one already present.
[photo=medium]4107[/photo]
You will have to find the diode leaving your modulation transformer and add one or more in series to lower your dead key. The photo i posted is of a Cobra 19 DX mobile, that may or may not be similar to your Uniden 510. The same basic principal applies to all transformer modulated radios.

Hope that helps..
-Leap

 

[gr1m]

what deadkey would you recommend for my lil amp?

 

[LeapFrog]

Well I just layed out an idea on how to lower the dead key. What you do with the information is up to you.

Was this amp sold to you as a high-drive amp?
Honestly I am not familiar enough with the SD1446 to tell you if you can drive that box with a 3 watt dead key..

I know most mosfet amps require no more than around 1.5- 2 watts, your box maybe just fine to drive with a factory radio but please get a confirmation from someone who knows..

 

[gr1m]

well i bought the amp from a friend of mine he told me to make sure i lower the dead key on my radio. I had a cobra 25 keying 1 watt swinging 4 watts according to my Mattco PX1000 peak reading meter but went out yesterday to try to get in on some dx and the cobra dont have output anymore so gonna use the little 510 till i figure out the problems with the cobra or buy another radio, but from info i have found on the net and along with pics the amp seems and looks like a Palomar 225 or a 250.

 

[LeapFrog]

A quick google search later:

Not a lot of input is need for this amp - 1 watt in will = 100 watts out. Modulating to 12 watts on AM = 200 watts out of the amplifier.

I actually have set the input deadkey to .5 watts to get the amp to deadkey around 50-60 watts and swing upwards to 200 watts following the 1/4 ratio rule.

Since this amp doesn't require a lot of input you really shouldn't drive them with more than 2 watts input as you'll sound garbled and the life of the amplifier with be drastically shortened. Of course there are always the people that will tell me that they've been running a stock radio with a 5 watt deadkey into their amp for 2 years with no problems and good for them, but it's definitely not what I would recommend.

Found @ http://www.cbradiomagazine.com/Amplifier Reviews/Palomar Elite 250/Palomar Elite 250 Review.html

It uses the same transistors so I would follow those guidelines..
Also be aware if the amp has a problem your friend didn't tell you about like improper input-output tunes, you may be seeing a high amount of power reflected back into the radio (high SWR). Which might have killed the Cobra 25, have you checked swr through the amp while it was off?.

 

[gr1m]

when i first hooked up the amp i had the stated meter after the amp and was checking swr and with amp off i was getting 1.1 and with the amp on i was getting 1.3. but i will try what you said about the diode mod and get back with you and let you know the results. I was thinking bout just reducing the deadkey with the tuning slug.

 

[LeapFrog]

when i first hooked up the amp i had the stated meter after the amp and was checking swr and with amp off i was getting 1.1 and with the amp on i was getting 1.3. but i will try what you said about the diode mod and get back with you and let you know the results. I was thinking bout just reducing the deadkey with the tuning slug.

I seriously doubt that you may be able to do it with just a tuning slug, I don't know though..

Disclaimer:
I take no responsibility for what you do inside your radio, keep that in mind (if you break something it's on you). It may be illegal to transmit on a modified radio/using a power amplifier in your country, keep that in mind & always check your local & national regulations before modifying a transceiver..

Now that that's out of the way, have fun & enjoy!!

 

[gr1m]

ok i got 2 1N4003 diodes and put them in series with the one in there and it just dropped the deadkey from 4 watts to 3 gonna take them out and see if i can drop it to 1 watt with the slug.

 

[LeapFrog]

ok i got 2 1N4003 diodes and put them in series with the one in there and it just dropped the deadkey from 4 watts to 3 gonna take them out and see if i can drop it to 1 watt with the slug.

What slug? One maybe for the 54Mhz Second Harmonic Trap, most all slugs should not be adjusted unless you have some very expensive test equipment. Have you looked online to determine what to adjust? You may have better results by adding one more diode and then adjusting a slug?!

I know literally nothing about the Uniden 510/520 radios so I am afraid I cannot help you anymore regarding this process. If you look into the Cobra swing kits (resistor and capacitor) you could in theory apply the same idea to your radio, then the resistor value determines the dead key level... But I don't have enough knowledge to tell you how it's done on just any/that radio..

-Leap

 

[gr1m]

The PRO 510 XL models made from 1999 up, have changed. The AMC is D-203 and the power adj. is now L-203

found @ http://www.copperelectronics.com/discus4/messages/3847/6895.html?1070048376

L-203 is the slug i am adjusting. i screwed it down and it got to 1 watt and i kept going and the wattage came back up so i brought it up to 1 watt and left it dont have much swing tho lol.

 

[LeapFrog]

The PRO 510 XL models made from 1999 up, have changed. The AMC is D-203 and the power adj. is now L-203

found @ http://www.copperelectronics.com/discus4/messages/3847/6895.html?1070048376

L-203 is the slug i am adjusting. i screwed it down and it got to 1 watt and i kept going and the wattage came back up so i brought it up to 1 watt and left it dont have much swing tho lol.

You might not need much swing though if you are going to run power, I can't tell you though because I don't run power and don't have enough experience with amplifiers to know.

 

[gr1m]

well Leapfrog i have never been the guy that has been the one to want big swing anyways all im worried about is sounding nice and clear over the air and having a low deadkey so my amp lasts forever so i can make a dx contact every now and then.

 

[gr1m]

well LeapFrog if ya still on friend droped deadkey with the slug and getting 1 watt swinging 2 with a good audio into mic and thats not yelling just talking normal. put it in truck and turned the amp on low power 20 watt deadkey swinging 60 medium 70 swinging 100 130 maybe then high 125 deadkey i guess swinging by the 150 mark and just got done talking to 311 in Indiana and said it was nice and clear and not distorted. so im happy with my lil setup thanks for your help if i knew how to add you i would

 

[LeapFrog]

No need to "add me", i'm still relatively new to the radio world. But if you want to you can click on my profile image and view my account/profile page, there is a "Follow" button I don't know what it does yet but I think you get updates whenever I post something??

You can do that if you like, but a lot of stuff is still beyond my understanding..
I am glad you got it going with clear Audio!!!
That makes me happy when something works out.

All The Best.
-Sam aka LeapFrog