Forums :: Resources :: Features :: Photo Gallery :: Vintage Radio Shows :: Archives
Support This Site: Contributors :: Advertise


It is currently Aug Tue 04, 2020 8:45 pm


All times are UTC [ DST ]





Post New Topic Post Reply  [ 30 posts ]  Go to page 1, 2  Next
Author Message
 Post subject: Are there any RF tube amp experts out there?
PostPosted: Oct Fri 04, 2019 5:25 pm 
Member
User avatar

Joined: Jul Tue 29, 2014 12:25 am
Posts: 229
Location: Las Vegas, Nevada
Can anyone tell me in simple terms the path of a signal thru a 1x3 tube amp.

The mic is keyed and comes into the amp then where does it go.
Does it go to the transistor that engages the relays or does it go to the driving 6LF6 tube that then sends voltage to the output tubes which then engages the relay?

I'm trying to track down why the relays are not engaging but if I manually push the lower relay closed, the amp works and has output.
I'm not getting voltage from somewhere to engage the relays.

Attachment:
relay resize.jpg
relay resize.jpg [ 322.3 KiB | Viewed 2051 times ]

Attachment:
20190921_062607-800x450.jpg
20190921_062607-800x450.jpg [ 330.52 KiB | Viewed 2046 times ]


Top
 Profile  
 
 Post subject: Re: Are there any RF tube amp experts out there?
PostPosted: Oct Fri 04, 2019 6:07 pm 
Member

Joined: Aug Sat 17, 2019 8:55 pm
Posts: 63
Input is a mic with push-to-talk? Usually, the push to talk is simply a push button switch that completes the circuit to energize the relay. It could be directly or it could be through a 'buffer' of some kind. Would need to see more of the circuit to make any more detailed suggestions.

What has this got to do with RF?


Top
 Profile  
 
 Post subject: Re: Are there any RF tube amp experts out there?
PostPosted: Oct Fri 04, 2019 6:12 pm 
Member
User avatar

Joined: Jul Tue 29, 2014 12:25 am
Posts: 229
Location: Las Vegas, Nevada
It's an RF amplifier

Let's ignore the pictures and tell me simply how does the signal travel through a simple 1 transistor with 1 driving tube and 3 output tube?

Thanks


Top
 Profile  
 
 Post subject: Re: Are there any RF tube amp experts out there?
PostPosted: Oct Fri 04, 2019 9:26 pm 
Member
User avatar

Joined: Jun Sat 18, 2011 3:36 am
Posts: 2383
Location: Milton, FL 32570
radiocom wrote:
It's an RF amplifier

Let's ignore the pictures and tell me simply how does the signal travel through a simple 1 transistor with 1 driving tube and 3 output tube?

Thanks

Provide a schematic an I'm sure some can help you. Help us help you.

_________________
Thanks,
Jason
N1EBC


Top
 Profile  
 
 Post subject: Re: Are there any RF tube amp experts out there?
PostPosted: Oct Fri 04, 2019 9:36 pm 
Member
User avatar

Joined: Jul Tue 29, 2014 12:25 am
Posts: 229
Location: Las Vegas, Nevada
Thanks for the reply but this one is homebrew and no schematic was ever drawn.


Top
 Profile  
 
 Post subject: Re: Are there any RF tube amp experts out there?
PostPosted: Oct Fri 04, 2019 9:55 pm 
Member

Joined: Aug Sat 17, 2019 8:55 pm
Posts: 63
Most likely, the input is applied to the control grid of the driver tube. Output taken from the plate. The outputs could be either common cathode with the signal applied to the control grid, or grounded grid with the input signal applied to the cathodes. In either case, the output comes from the plates into an impedance matching network (often a pi network) and feeds the antenna port.


Top
 Profile  
 
 Post subject: Re: Are there any RF tube amp experts out there?
PostPosted: Oct Fri 04, 2019 10:32 pm 
Member
User avatar

Joined: Jul Tue 29, 2014 12:25 am
Posts: 229
Location: Las Vegas, Nevada
Thanks Ylli.

do you know where the transistor comes in to play?

Is it during input or output?


Top
 Profile  
 
 Post subject: Re: Are there any RF tube amp experts out there?
PostPosted: Oct Fri 04, 2019 10:35 pm 
Moderator
User avatar

Joined: Jan Thu 01, 1970 1:00 am
Posts: 21784
Location: Somers, CT
It appears to use RF sensing on the input to key the change over relays. I think I see a detector diode near the so-239.

_________________
Just because it can be done doesn't mean it should be done.


Top
 Profile  
 
 Post subject: Re: Are there any RF tube amp experts out there?
PostPosted: Oct Fri 04, 2019 10:40 pm 
Member
User avatar

Joined: Jul Tue 29, 2014 12:25 am
Posts: 229
Location: Las Vegas, Nevada
Peter .... can you describe it to me?

is it the clear what I thought were transistors?

Thanks


Top
 Profile  
 
 Post subject: Re: Are there any RF tube amp experts out there?
PostPosted: Oct Fri 04, 2019 10:44 pm 
Member

Joined: Jun Sat 15, 2019 7:43 pm
Posts: 791
A linear with a driver tube is usually designed for illegal CB use. Do you have a ham license?

DM


Top
 Profile  
 
 Post subject: Re: Are there any RF tube amp experts out there?
PostPosted: Oct Fri 04, 2019 10:49 pm 
Member
User avatar

Joined: Jul Tue 29, 2014 12:25 am
Posts: 229
Location: Las Vegas, Nevada
Of course and none of your business !!!


Top
 Profile  
 
 Post subject: Re: Are there any RF tube amp experts out there?
PostPosted: Oct Fri 04, 2019 11:11 pm 
Member
User avatar

Joined: Jun Sat 18, 2011 3:36 am
Posts: 2383
Location: Milton, FL 32570
radiocom wrote:
Of course and none of your business !!!

A little snippy aren't since YOU are asking for help.

How about trying to sketch out a rough schematic it will only help your learning.

_________________
Thanks,
Jason
N1EBC


Top
 Profile  
 
 Post subject: Re: Are there any RF tube amp experts out there?
PostPosted: Oct Fri 04, 2019 11:15 pm 
Member
User avatar

Joined: Jul Tue 29, 2014 12:25 am
Posts: 229
Location: Las Vegas, Nevada
I apologize because I meant it jokingly and after i read it , it does sound rude. Sorry


Top
 Profile  
 
 Post subject: Re: Are there any RF tube amp experts out there?
PostPosted: Oct Sat 05, 2019 12:06 am 
Member
User avatar

Joined: Jan Thu 01, 1970 1:00 am
Posts: 3993
Trying again:

1. Did you fix the broken transistor referenced in the previous posting on this amplifier?
https://antiqueradios.com/forums/viewtopic.php?f=12&t=365188

2. Does the schematic below correlate with your unit? (6LF6 can substitute for EL509 with mods)

Image


Top
 Profile  
 
 Post subject: Re: Are there any RF tube amp experts out there?
PostPosted: Oct Sat 05, 2019 12:42 am 
Member
User avatar

Joined: Jul Tue 29, 2014 12:25 am
Posts: 229
Location: Las Vegas, Nevada
Macrohenry .... thank you. I did replace the transistor but no data sheet is available for a 2n600 to know which is emitter, base and collector so I tied it in the same as the old one. I'm thinking the collector should go to ground. I'm not sure

I am studying the schematic and will be back to you shortly or tomorrow because I have some errands to run.

I started this new thread because I was asking a different question.

Thank you


Top
 Profile  
 
 Post subject: Re: Are there any RF tube amp experts out there?
PostPosted: Oct Sat 05, 2019 2:48 am 
Member
User avatar

Joined: Jun Sat 18, 2011 3:36 am
Posts: 2383
Location: Milton, FL 32570
2n600 or a 2n6000

2n6000 is a NPN
How to identify transitor pinout with a multimeterhttp://www.electricalbasicprojects.com/how-to-identify-npn-and-pnp-transistor-using-multimeter/

_________________
Thanks,
Jason
N1EBC


Top
 Profile  
 
 Post subject: Re: Are there any RF tube amp experts out there?
PostPosted: Oct Sat 05, 2019 9:18 pm 
Member
User avatar

Joined: Dec Sat 24, 2011 9:17 pm
Posts: 6298
Location: Vancouver Island, Canada
Remember this for next time - to ask a new question about the same unit, go back to you very 1st post, Edit, then change the title of the post. These experts are smart enough to go to the last post, where they find the latest info.

All one thread keeps the history of the unit before the new question without searching for it or having to ask for details.

#2, If you make a 'possibly snarky' response, be polite, and say it with a smile. :lol:

_________________
Watch the doughnut, not the hole.
Burl Ives, RIP, oldtimer.
[:l>)


Top
 Profile  
 
 Post subject: Re: Are there any RF tube amp experts out there?
PostPosted: Oct Sat 05, 2019 10:50 pm 
Member
User avatar

Joined: Jul Tue 29, 2014 12:25 am
Posts: 229
Location: Las Vegas, Nevada
Thanks WestCoast for the advice. I Will heed that.


Top
 Profile  
 
 Post subject: Re: Are there any RF tube amp experts out there?
PostPosted: Oct Sun 06, 2019 11:39 am 
Member
User avatar

Joined: Jul Tue 29, 2014 12:25 am
Posts: 229
Location: Las Vegas, Nevada
The 2n600 is a pnp ger from what I could find. 2n600 looks like a bolt.

Machenry.... the schematic is similar but more components than what I'm trying to repair so I'm having difficulty trying to follow the path.


Top
 Profile  
 
 Post subject: Re: Are there any RF tube amp experts out there?
PostPosted: Oct Sun 06, 2019 2:05 pm 
Member
User avatar

Joined: Jun Sat 18, 2011 3:36 am
Posts: 2383
Location: Milton, FL 32570
Transistor pinouts there is one with a stud in the pic
http://www.radio.imradioha.org/Images/Base_Diags.jpg

_________________
Thanks,
Jason
N1EBC


Top
 Profile  
 
Post New Topic Post Reply  [ 30 posts ]  Go to page 1, 2  Next

All times are UTC [ DST ]


Who is online

Users browsing this forum: No registered users and 15 guests



Search for:
Jump to:  


































-->


Privacy Policy :: Powered by phpBB