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Alan 9001 final problem

R

Rogerbird1

Well-Known Member
Apr 24, 2002
522
117
53
Massachusetts
rogerbird.tripod.com
Hi,

Sorry to hear of your troubles.

First of all, If your going to try to use a 2SC1969, for a final, you MUST use the Insulator. The Mounting tab CANNOT be grounded.

In the 2SC1969 the mounting tab is the Collector, in the MRF477 the mounting tab is the Emitter.



You probably will not get full power with the 2SC1969, but it should work a little. (possibly 4 watts am or so).



I would replace the blown final with a MRF455 final. Wire it properly and then remove C132, (I think its marked the same in the Alan).

This should give you nearly 10W am 25W Ssb (like stock) at least.



See my site for mod info (or others) at:

www.cbtricks.com/~rogerbird/2510/3rf.htm

see Mod2.

If you need more help, Email me.

Roger




</p>Edited by: <A HREF=http://p067.ezboard.com/bworldwidecbradioclub.showUserPublicProfile?gid=rogerbird1>Rogerbird1</A> at: 11/2/04 10:50 pm
 

Hi,

Sorry to hear of your troubles.

First of all, If your going to try to use a 2SC1969, for a final, you MUST use the Insulator. The Mounting tab CANNOT be grounded.

In the 2SC1969 the mounting tab is the Collector, in the MRF477 the mounting tab is the Emitter.



You probably will not get full power with the 2SC1969, but it should work a little. (possibly 4 watts am or so).



I would replace the blown final with a MRF455 final. Wire it properly and then remove C132, (I think its marked the same in the Alan).

This should give you nearly 10W am 25W Ssb (like stock) at least.



See my site for mod info (or others) at:

www.cbtricks.com/~rogerbird/2510/3rf.htm

see Mod2.

If you need more help, Email me.

Roger




</p>Edited by: <A HREF=http://p067.ezboard.com/bworldwidecbradioclub.showUserPublicProfile?gid=rogerbird1>Rogerbird1</A> at: 11/2/04 10:50 pm
 
If you are getting 50 Ohms, that is where your Current short is.

The Mounting tab of the 2SC1969 is the collector which is 13V. It MUST be Isolated from ground.



Try lifitng one leg of the Bias Diode (across the final) it may be damaged. It should read between 500 and 1600 Ohms across a good Bias diode. If it is shorted or open, that could be the cause of the inability to lower the Bias Voltage.(and the high current)



Roger






</p>
 
If you are getting 50 Ohms, that is where your Current short is.

The Mounting tab of the 2SC1969 is the collector which is 13V. It MUST be Isolated from ground.



Try lifitng one leg of the Bias Diode (across the final) it may be damaged. It should read between 500 and 1600 Ohms across a good Bias diode. If it is shorted or open, that could be the cause of the inability to lower the Bias Voltage.(and the high current)



Roger






</p>
 
Ok.

Try removing the final from the circuit, and see if the high current is still there. If so then the proble is elsewhere, maybe the driver is bad or something else.



If the problem goes away (no high Current ) then the 2SC is NOT a suitable replacement or is bad.



The MRF477 and its direct replacement the MRF497 have very different gain from the 2SC1969 as well as a different pin out.



There was a lenghthy discussion on this message board a while back, regarding suitable replacement/subsitutions for the MRF477.



The best alternative would be the MRF455. Same gain, "Q" but different case style.



one more thing...

What voltage do you have on the TAB of the 2SC? in RX and TX?



Roger


</p>
 
Ok.

Try removing the final from the circuit, and see if the high current is still there. If so then the proble is elsewhere, maybe the driver is bad or something else.



If the problem goes away (no high Current ) then the 2SC is NOT a suitable replacement or is bad.



The MRF477 and its direct replacement the MRF497 have very different gain from the 2SC1969 as well as a different pin out.



There was a lenghthy discussion on this message board a while back, regarding suitable replacement/subsitutions for the MRF477.



The best alternative would be the MRF455. Same gain, "Q" but different case style.



one more thing...

What voltage do you have on the TAB of the 2SC? in RX and TX?



Roger


</p>
 
Hello friends

I have a Alan 9001 (Lincoln clone).I had a problem with

radio because some people tuned it up the output power.So my MRF477 was dead,because consumption

from power supply was a 5-8amps with no modulation

in SSB mode.(Also no output power from radio)So I give as a final 2SC1969 output only 10-12w in SSB but works great with external AMP..I both a new stock MRF477 give the trimmer vr112 113 to minimum,but situation is the same.Impossible get the current between 1-2 amps.Consumption from supply is great and the same with or without modulation.WIth modulation radio normally work,but current is dramatically going up.Started at 4-5amps and going up.Also with the 2SC1969 is possible get current only between 1,5-2.5 amps.

What it means?I tried final with or without insultator.No

change.When I am in FM mode and give RF power to

minimum current is max,when give to a center going little

down and give to a max go also to maximum 5-7 amps.

I tried it only a few seconds,becasue the current go dramatically up.Please friends give me any tip or solution

from this situation.Sorry for my simple english,maybe

understand me

73 TOM 330AT112


</p>
 
Hello friends

I have a Alan 9001 (Lincoln clone).I had a problem with

radio because some people tuned it up the output power.So my MRF477 was dead,because consumption

from power supply was a 5-8amps with no modulation

in SSB mode.(Also no output power from radio)So I give as a final 2SC1969 output only 10-12w in SSB but works great with external AMP..I both a new stock MRF477 give the trimmer vr112 113 to minimum,but situation is the same.Impossible get the current between 1-2 amps.Consumption from supply is great and the same with or without modulation.WIth modulation radio normally work,but current is dramatically going up.Started at 4-5amps and going up.Also with the 2SC1969 is possible get current only between 1,5-2.5 amps.

What it means?I tried final with or without insultator.No

change.When I am in FM mode and give RF power to

minimum current is max,when give to a center going little

down and give to a max go also to maximum 5-7 amps.

I tried it only a few seconds,becasue the current go dramatically up.Please friends give me any tip or solution

from this situation.Sorry for my simple english,maybe

understand me

73 TOM 330AT112


</p>
 

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