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Onelasttime
New member
Username: Onelasttime

Post Number: 3
Registered: 8-2011
Posted on Friday, August 05, 2011 - 11:57 pm:   Edit Post Delete Post    Move Post (Moderator/Admin Only)

Ok I have radio's I can turn down to 2-3 watt's if I have too but would prefer not to have to do that. Instead of putting a swamping resistor in the front end or bypassing the drive tube could I do this???? Turn the driver tube location into a third tube identical to the other final two tubes and use one of my higher output radio's to drive the now high drive amp since it would not have it's own driver???

I can replace diodes and cap's and such but I do not know enough about circuit design to do this myself. Any idea who could do it?????

I have one radio with a MRF 455 final that is more then able to drive a 3 6LQ6 AMP and I have full control of the RF output so it would be ideal.........I am afraid that this radio even turned down to 1 watt would swing far too much pep wattage into the amp for clean operation as it is. The radio's I do have that I could turn down to 2-3 watt's and not have them swing much past 4 watt's really do not have that much capacity, limited modes of operation, and narrow band width etc.....

To be honest I think my bone stock 20 year old warranty seal still in place Uniden PC122 put's out a 4 watt dead key and swings to like 6 and that is stock so why in the world a company would make an amp that needed 2-3 watt's of dead key boggles my mind?!?!?!

Was it common in pre 1980's for radio's to put out under 4 watt's from the factory??? Keep in mind I am only 38 years old so I do not really know what was going on before the 1980's very well because I was a little kid!LOL

Oh and I am not really out for more power that is not the reason for asking about converting it. I just would like to make it more user friendly for export and amateur radio's.

Also given seeing how most CB's do not have a low and high power adjustment just AM power, SSB power and ALC etc.......can you set up the run of the mill FCC type certified CB to dead key 1 watt and swing to it's peak and not have it be a splatter box? I do not why I am even asking this I almost never talk AM anyways usually always SSB but figured I should ask. Seeing how I have owned RCI and Lincolns and the like since 1991/92 I really do not have much experience setting up small FCC type certified CB with an amp.Kind of been spoiled with an RF knob to dial my power up and down.LOL

Eventually I want to convert this amp to 12 or 6 meter for my son once he get's his license.So it will probably see a lot of use for a long time to come so the extra tube would not go to waste.
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Dale
Senior Member
Username: Dale

Post Number: 1752
Registered: 12-2002
Posted on Saturday, August 06, 2011 - 7:20 pm:   Edit Post Delete Post    Move Post (Moderator/Admin Only)

im not sure what those tubes will handle far as
drive is concerned .but what i do is use 1 watt
dead key then if ya think your pep is too high
turn back the mic gain some.or if ya know how much the amp will do pep [swing] max then adjust
the micgain to that.i do this with a dual mosfet
magnum going into a 2 pill amp. works fine
dale/a.k.a.hotrod
cef426
cvc#64
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Tech833
Moderator
Username: Tech833

Post Number: 2015
Registered: 8-2002
Posted on Sunday, August 07, 2011 - 12:00 pm:   Edit Post Delete Post    Move Post (Moderator/Admin Only)

I've never heard of an amateur amp that uses 6LQ^ tubes. What make/model is it?
Your radio 'Mythbuster' since 1998
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Onelasttime
Junior Member
Username: Onelasttime

Post Number: 44
Registered: 8-2011
Posted on Sunday, September 04, 2011 - 3:14 am:   Edit Post Delete Post    Move Post (Moderator/Admin Only)

It is not an Amateur Amp from the a reality stand point in spite of the sticker on back telling the owner that it is a 6 and 10 meter amp and not to use it for CB radio.

In spite of that fact it is a very very clean design. It use's a very nicely designed voltage rectifier, the PI network is excellent and all the parts inside are top notch. From the stand point of design, layout, component selection it is a very clean amp. It is a Kris Power Pump. It has 1 X 6JB6 driving 2 x 6LQ6. The caps in this unit are Dublier and Sprage . Their are only two wax covered caps and those will be replaced too. The driver tested out at 90% and the finals tested at 90% and 95%.

I am thinking about removing the driver from the circuit and making it a 3 tube amp since the son will more then likely have a radio in the 50watt to 100 watt power output.

I will probably either add in another 6LQ6 for a total of 3 or I will gut the amp and install . Keep in mind I am not going to use this on 11 meter band. The use of the CB is to test it into a dummy load.

Their is no shortage of glass and ceramic tubes that could be used in this amp if you are will to change out the socket's and re-tune the PI network. Granted they are all going to obsolete but I will just buy a couple of spare's at the same time.

If I have to choose between a TV sweep tube and a RF Amp specific tube I take the latter! The price has gotten really high on 6LQ6 tubes and even worse for the 6JG6. To the point that buying up surplus Amateur tubes with higher output for the same power consumption or Russian tubes which are dirt cheap.

I hate to buy 100 watt and lower sweep tubes at the same price as much better RF specific tubes. A matched pair of NOS 6LQ6 is $160 and 99% of the 6JG6's I run across are used and often the seller does not have the tools to test them.

Generally or rather lately when I buy tubes I buy double the number I need to make sure I have enough to keep the Amp going for the rest of my life or more to the point my son from 13 to at least 35 years of age.

For example I plan on building an HF amp for my son. I want to use 2 Russian GI-7BT tubes. So I bought 5 of them. This way I have enough spares to keep the amp going for a long time
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Spiderleggs
Junior Member
Username: Spiderleggs

Post Number: 49
Registered: 5-2002
Posted on Friday, September 09, 2011 - 5:30 pm:   Edit Post Delete Post    Move Post (Moderator/Admin Only)

The GLA 1000 used 6lq6 tubes.

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