Image

D&A maverick 250 load-tune??????'s

This is the place to ask questions about linear amplifiers, or power supplies

Moderator: JR Moderator

User avatar
TICKDOG
4 PILL USER
4 PILL USER
Posts: 32
Joined: Sunday, 14 December 2008, 6:53 AM
Name: chuck
Location: PALATKA, FL

D&A maverick 250 load-tune??????'s

Post by TICKDOG » Sunday, 21 December 2008, 20:19 PM

I just got my first tube type amp and need to figure out how to set it up. I know you have to load and tune it, but is there a procedure I should be following? there's a 'load' nob and a 'tune' nob. there is also a smaller 'driver tune' nob and a 'load' nob towards the bottom of the amp. just put new tubes in and don't want to mess up. I've also seen in some posts about setting your amp at 80%. my radio dk 3, swingin 9 on a pdc 700 peak meter, is it safe to drive this kind of amp with swing and mod upgrades? don't know alot about tube boxes so any help and direction will be used and appreciated!
unit "FIFTY~83"...Palatka,FL




User avatar
Foxhunter
Donor
Donor
Posts: 2662
Joined: Thursday, 03 April 2008, 10:24 AM
Radio: Fisher-Price
Location: South-Central New Jersey
Referrals: 1

Post by Foxhunter » Sunday, 21 December 2008, 21:37 PM

Welcome on the Forum here Tickdog and Season's Greetings from New Jersey. Saw your post go unanswered and thought to share what I found a short time back for another member here named Okie who'd just bought a D&A amp and needed operating tips for it. I wrote him the following information when he first got his D&A Maverick. He may be a good one to ask for any additional information as he's possibly become more familiar with using it since.
Foxhunter wrote:
The D&A Maverick

"Those amps where built for radios that didn't do more than 5 watts or so am and 12 watts ssb

The "driver" tubes for that amp are 6jg6 tubes (x 4)
The "final" tubes for that amp are 6lq6 / 6mj6 / 6je6c tubes (x 4)

If its Gray in color it has a "keying tube" in it.
If its Biege/Tan or 2-tone Brown it has "electronic keying".

You have to remember that when these amps where built, CB's only did 5 or so watts.
If your radio swings more than 12W~15W, you will wipe out your 6jg6's tubes !
10 watts input would swing about 475W to 525W on high. Some claim even a little more.
Most Mavericks will key 250W and swing to 500W+ with stock tubes.

*How to tune a maverick*
-Turn on amp wait for it to warm up ( 10 to 15 mins ).
-Key amp with it on hi top meter should be working.
-Use the meter on the amp----NOT your watt meter.
-Tune so all load and tune knobs max the meter out (as high as the meter will read) on the back of the amp is a tune knob do the same but you ONLY need to this one once ADJ for max meter reading ( unless you change radio's ).
-Take the top left Load control knob and turn it clock wise so meter drops back about 3 to 4 lines on meter ( milliamps ).
-This is called "over coupling", it cleans up the audio and lets the amp swing."
Follow these few links here for some additional info or pic's on the D&A Maverick:
(Video demo): http://www.lcr-europe.org/meter/c,k/vid ... ter,5217,0
http://home.ptd.net/~n3cvj/damaverick250.htm
http://www.shadowstorm.com/cb/Classic_C ... fiers.html
http://www.ootw.com/cbradio/classic_cb_radios.htm

Hope this helps!

Foxhunter

I Remember


Image



User avatar
420Snowman
Donor
Donor
Posts: 1369
Joined: Wednesday, 07 April 2010, 9:08 AM
Radio: Snowman Built 29
Antenna: Shockwave
Name: DJ
Location: Show-Me State!!!
Contact:

Re: D&A maverick 250 load-tune??????'s

Post by 420Snowman » Saturday, 26 February 2011, 18:51 PM

I know this is an ancient post, but I have the same DA Maverick "dual power" and it doenst have any hi and low switch, Nor a tune knob on the back. I am only seeing about 150 dK swinging 300 or so. I would like to see a lot more from this and the tubes all recently tested out at 90% at a local shop so I am confused on why its only doing this much. I am driving it with anywhere from 3-9 watts, any help is appreciated!!

Snowman
Rolling the Snowman Built Gateway Mobile
16 pill Snowman Built
Snowman Built Cobra 29 LX
Davemade coil stabbed in the roof



User avatar
Nagant
Donor
Donor
Posts: 1339
Joined: Thursday, 31 December 2009, 4:15 AM
Radio: To Many To List
Antenna: M104C, V-Quad
Name: Paul
Location: Southern Illinois
Referrals: 1

Re: D&A maverick 250 load-tune??????'s

Post by Nagant » Sunday, 27 February 2011, 5:35 AM

420Snowman wrote:I know this is an ancient post, but I have the same DA Maverick "dual power" and it doenst have any hi and low switch, Nor a tune knob on the back. I am only seeing about 150 dK swinging 300 or so. I would like to see a lot more from this and the tubes all recently tested out at 90% at a local shop so I am confused on why its only doing this much. I am driving it with anywhere from 3-9 watts, any help is appreciated!!

Snowman

The Maverick, as well as the other D&A amps, went through many changes through the years. Yours sound like it could be an earlier model. You need somewhere between 14 to 20 watts peak input to see full output from one. They run best with 2 to 3 watts of carrier input. The Mavericks were generally 8 tube amps with four driving four. I haven't seen one of those earlier units in person and thus I'm curious how many tubes yours is?

What sort of meter are you using? On a true active reading peak meter with good tubes the eight tube Maverick 250's will do 500 to 750 watts peak depending on the drive. If your using a CB meter I couldn't even venture a guess as to what output you should see. I use a tone from a signal generator and tune for max peak output. That's just my tune method, many others have their own method.

On a side note. You say a local shop checked your tubes. There is a huge difference in tube testers. If they didn't use a good mutual conductance tester or electromagnatic I wouldn't put any faith in their testing.
Worm on AM or 262 on SSB.


Pills are for swallowing!



My YouTube CB Radio Channel http://www.youtube.com/user/262NagantRa ... e=mhee#p/u



User avatar
Chester
Duckplucker
Duckplucker
Posts: 166
Joined: Saturday, 02 February 2008, 13:08 PM
Location: Central Oregon
Referrals: 1

Re: D&A maverick 250 load-tune??????'s

Post by Chester » Wednesday, 02 March 2011, 17:19 PM

Snowman, I am presently running a Maverick 250, does yours have a toggle switch that says "power" ? Also I have a owners manual that was sent to me by email, PM me your email address and I'll forward it to you. Great little amp, mine really steps right out there.
Chester 221


User avatar
preacherman
Donor
Donor
Posts: 1282
Joined: Friday, 09 February 2007, 20:13 PM
Name: Bob
Referrals: 2

Re: D&A maverick 250 load-tune??????'s

Post by preacherman » Thursday, 03 March 2011, 6:12 AM

The switch that says power...if it's about the third one in from the right is the hi/lo switch on the
newer "tan and brown" Mavericks. With good tubes and a well tuned Cobra 29, you will see, as
nagant says about 7-800w. I have seen one do 900 peak on an accurate meter, but it has all new tubes
and was driven to do all it was capable of.

Great amps...I have a tan and brown and my friend 222 has a grey one. Great smooth audio, quick
warm up and an excellent driver if you are going to run something bigger 8)
Preacherman
"Preacherman workin' this mudduck mercury. Topside, Land O' Lincoln"



User avatar
Nagant
Donor
Donor
Posts: 1339
Joined: Thursday, 31 December 2009, 4:15 AM
Radio: To Many To List
Antenna: M104C, V-Quad
Name: Paul
Location: Southern Illinois
Referrals: 1

Re: D&A maverick 250 load-tune??????'s

Post by Nagant » Thursday, 03 March 2011, 6:45 AM

Is it tan/brown? If so it's the later Maverick before they switched to calling them the MDX200. I missed the Dual Power label you mentioned in your original post. Preacherman is correct there should be a Hi/Low switch like he mentions. I've never seen a Maverick 250 without one. If you are trying that switch and seeing no difference then it's highly likely the switch is bad in one position. I've seen that happen a number of times to D&A's through the years.
Worm on AM or 262 on SSB.


Pills are for swallowing!



My YouTube CB Radio Channel http://www.youtube.com/user/262NagantRa ... e=mhee#p/u




Post Reply Previous topicNext topic

Who is online

Users browsing this forum: No registered users and 4 guests