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


It is currently Aug Sat 19, 2017 7:30 pm


All times are UTC [ DST ]





Post New Topic Post Reply  [ 431 posts ]  Go to page Previous  1 ... 10, 11, 12, 13, 14, 15, 16 ... 22  Next
Author Message
 Post subject: Re: marconi model 160
PostPosted: Jan Mon 09, 2017 11:59 pm 
Member

Joined: Mar Fri 07, 2014 10:20 am
Posts: 1630
I checked it with the speaker and no noise and I even checked the speaker with a 9v battery also I will send a pic of that white wire


Top
 Profile  
 
 Post subject: Re: marconi model 160
PostPosted: Jan Tue 10, 2017 12:03 am 
Member

Joined: Mar Fri 07, 2014 10:20 am
Posts: 1630
here is the pic of the white wire that goes no where


Attachments:
DSC00133.JPG
DSC00133.JPG [ 112.77 KiB | Viewed 325 times ]
Top
 Profile  
 
 Post subject: Re: marconi model 160
PostPosted: Jan Tue 10, 2017 12:20 am 
Member
User avatar

Joined: Mar Tue 13, 2012 6:56 am
Posts: 1014
Location: San Diego
Where in the schematic is the white wire connected?

Do you have a low level audio source you can access with a plug & cable such as a cellphone or stereo with line level out, etc.? Connect it to the radio, ground lead to chassis and signal lead through a .1 cap to grid cap of 6Q7. See if you can hear the audio through the radio.

Matt


Top
 Profile  
 
 Post subject: Re: marconi model 160
PostPosted: Jan Tue 10, 2017 12:26 am 
Member
User avatar

Joined: Mar Tue 13, 2012 6:56 am
Posts: 1014
Location: San Diego
Also, use spaghetti tubing or heat shrink tubing for insulation. Electrical tape is not the way to go.

Matt


Top
 Profile  
 
 Post subject: Re: marconi model 160
PostPosted: Jan Tue 10, 2017 12:30 am 
Member

Joined: Mar Fri 07, 2014 10:20 am
Posts: 1630
when you say line level out do you mean external speaker and has for the schematic and white wire I will have to look at it tomorrow but I know the white wire that you see goes to the if trans


Top
 Profile  
 
 Post subject: Re: marconi model 160
PostPosted: Jan Tue 10, 2017 12:39 am 
Member
User avatar

Joined: Mar Tue 13, 2012 6:56 am
Posts: 1014
Location: San Diego
I mean a low level audio signal like a headphone jack on a phone or stereo or computer. Not a high power audio output like a speaker connection.

Matt


Top
 Profile  
 
 Post subject: Re: marconi model 160
PostPosted: Jan Tue 10, 2017 12:45 am 
Member

Joined: Mar Fri 07, 2014 10:20 am
Posts: 1630
ok I will have to look around for something to use but the signal generator any idea what might be wrong because I already recapped it and used it and I will try to figure out where the white wire is on the schematic


Top
 Profile  
 
 Post subject: Re: marconi model 160
PostPosted: Jan Tue 10, 2017 12:57 am 
Member

Joined: Mar Fri 07, 2014 10:20 am
Posts: 1630
the white wire is on the connection point of L7 opposite the connection pins 4 and 5 of tube 6q7 and one end c-22 connects to it also


Top
 Profile  
 
 Post subject: Re: marconi model 160
PostPosted: Jan Tue 10, 2017 12:58 am 
Member
User avatar

Joined: Mar Tue 13, 2012 6:56 am
Posts: 1014
Location: San Diego
Here is the signal path for the 400 Hz audio output. Clean and inspect rotary switch S3. Check continuity of T1 windings. Check R6.

Attachment:
Hickok 288X audio 400 Hz.jpg
Hickok 288X audio 400 Hz.jpg [ 100.52 KiB | Viewed 318 times ]

Matt


Last edited by skylerca on Jan Tue 10, 2017 1:07 am, edited 1 time in total.

Top
 Profile  
 
 Post subject: Re: marconi model 160
PostPosted: Jan Tue 10, 2017 1:01 am 
Member

Joined: Mar Fri 07, 2014 10:20 am
Posts: 1630
thanks I will check that in the morning and also I posted what I think is the connection point of the mystery white wire


Top
 Profile  
 
 Post subject: Re: marconi model 160
PostPosted: Jan Tue 10, 2017 1:12 am 
Member
User avatar

Joined: Mar Tue 13, 2012 6:56 am
Posts: 1014
Location: San Diego
spsquires wrote:
the white wire is on the connection point of L7 opposite the connection pins 4 and 5 of tube 6q7 and one end c-22 connects to it also

Ok. This point should also be connected to R4 (1 Meg) and one lug of R5 (volume control). Are those connections still there?

Matt


Top
 Profile  
 
 Post subject: Re: marconi model 160
PostPosted: Jan Tue 10, 2017 11:46 am 
Member

Joined: Mar Fri 07, 2014 10:20 am
Posts: 1630
yes this point has r-4 I meg and one wire to the volume control but it also has this mystery wire


Top
 Profile  
 
 Post subject: Re: marconi model 160
PostPosted: Jan Tue 10, 2017 4:28 pm 
Member
User avatar

Joined: Sep Sun 11, 2016 5:39 pm
Posts: 248
Location: Ga
Is this the signal,generator or radio your working on?

_________________
Rich


Top
 Profile  
 
 Post subject: Re: marconi model 160
PostPosted: Jan Tue 10, 2017 5:13 pm 
Member
User avatar

Joined: Mar Tue 13, 2012 6:56 am
Posts: 1014
Location: San Diego
Devildog, we're working on both.

Squires, since the schematic shows that point has only 4 things connected (IF wire, C22, R4, R5), and we verified all of them, then the white wire is not needed. Somebody may have soldered it on as a temporary connection at one point.

Let's focus on the sig gen for a minute. Things will be easier if we know it's working right. Do you have a set of headphones with a stereo plug connector like this?

Attachment:
stereo plug.jpg
stereo plug.jpg [ 38.9 KiB | Viewed 280 times ]

Matt


Top
 Profile  
 
 Post subject: Re: marconi model 160
PostPosted: Jan Tue 10, 2017 5:16 pm 
Member

Joined: Mar Fri 07, 2014 10:20 am
Posts: 1630
no I do not have any head phones or are you just looking for the plug


Top
 Profile  
 
 Post subject: Re: marconi model 160
PostPosted: Jan Tue 10, 2017 5:27 pm 
Member
User avatar

Joined: Mar Tue 13, 2012 6:56 am
Posts: 1014
Location: San Diego
I was going to have you use the headphones to listen for the sig gen audio. Next time you have a chance, pick up a cheap $10 pair of headphones. In the meantime, let's try again with the permanent magnet speaker. Hook up the sig gen to it with the Output Multiplier on 400~A.F. and the Output Control at maximum. Listen with your ear next to the speaker for a faint tone.

Matt


Top
 Profile  
 
 Post subject: Re: marconi model 160
PostPosted: Jan Tue 10, 2017 6:07 pm 
Member

Joined: Mar Fri 07, 2014 10:20 am
Posts: 1630
no sound at all from the generator and the white looks to be a factory solder


Top
 Profile  
 
 Post subject: Re: marconi model 160
PostPosted: Jan Tue 10, 2017 6:33 pm 
Member

Joined: Mar Fri 07, 2014 10:20 am
Posts: 1630
I cleaned up the output control button and now have a noise in the speaker from 100 to 10 on the output control


Top
 Profile  
 
 Post subject: Re: marconi model 160
PostPosted: Jan Tue 10, 2017 6:45 pm 
Member
User avatar

Joined: Mar Tue 13, 2012 6:56 am
Posts: 1014
Location: San Diego
Ok, good. Now hook the sig gen to the radio. Black to chassis ground. Red through .1 cap to 6Q7 grid cap.

Matt


Top
 Profile  
 
 Post subject: Re: marconi model 160
PostPosted: Jan Tue 10, 2017 6:58 pm 
Member

Joined: Mar Fri 07, 2014 10:20 am
Posts: 1630
had the noise from the generator and lost it again


Top
 Profile  
 
Post New Topic Post Reply  [ 431 posts ]  Moderators: Marcc, Norm Leal Go to page Previous  1 ... 10, 11, 12, 13, 14, 15, 16 ... 22  Next

All times are UTC [ DST ]


Who is online

Users browsing this forum: davep44, VECHER, Yahoo [Bot] and 11 guests



Search for:
Jump to:  




















Privacy Policy :: Powered by phpBB