I hope that a 1968 radio isn't too new for the forum. This radio is in SAMS AR-57, which I don't own. The output from the tuner is weak on FM and there is no output on AM. Someone cut the lead on one of the resistors (4.7K) on the FM board. If it's re-connected FM becomes even weaker.
The schematic that's inside one of the covers is not so good. I cannot find the FM board or that resistor on it. If it's on that schematic I can't find it.
This radio has the brand name "Cartrol-Aire" on it and models FA 205 and FA 205EX listed on the schematic and on the label with the model number. Components say TEN on them inside. This has to be a TEN (Japanese Brand Name). The brand-name on this radio is probably what a USA company put on it.
What should I check? What is the secret to getting the main board out to replace the electrolytic capacitors?
Thanks,
Dave
Give me a couple of days to get that Sam's for you. I'll send it along to you .... most likely on Friday (super busy tomorrow)
Dennis.
That's fine. Something must be wrong or connecting that resistor would boost the output from the tuner instead of making it weaker.
Thanks very much,
Dave
:Dave,
:
:Give me a couple of days to get that Sam's for you. I'll send it along to you .... most likely on Friday (super busy tomorrow)
:
:Dennis.
Data has been emailed.
Dennis
You are going to have to email me and let me know which pages you received. I received some error messages telling me that your inbox is over-quota. Some of the pages were rejected by your mail-server.
There should be 14 pages in all sent via 9 separate emails.
Dennis
Sorry for 'butting in', however I did a search on the net for a TEN Model FA-205 Car radio trhat I have recently aquired, however I have no technical info or schematics..etc. Would you mind emailing me any info you have PLEASE? Many Thanks.
::Dave,
:You are going to have to email me and let me know which pages you received. I received some error messages telling me that your inbox is over-quota. Some of the pages were rejected by your mail-server.
:
:There should be 14 pages in all sent via 9 separate emails.
:
:Dennis
Dennis
Let me know which pages (should be 14 pages via 9 emails) you did not receive.
I got the following error message that your inbox is full.
Dennis
We're sorry. There's a problem with the e-mail address(es) you're trying
to send to.
...The e-mail message could not be delivered because the user's mailfolder is full.
: I hope that a 1968 radio isn't too new for the forum. This radio is in SAMS AR-57, which I don't own. The output from the tuner is weak on FM and there is no output on AM. Someone cut the lead on one of the resistors (4.7K) on the FM board. If it's re-connected FM becomes even weaker.
: The schematic that's inside one of the covers is not so good. I cannot find the FM board or that resistor on it. If it's on that schematic I can't find it.
: This radio has the brand name "Cartrol-Aire" on it and models FA 205 and FA 205EX listed on the schematic and on the label with the model number. Components say TEN on them inside. This has to be a TEN (Japanese Brand Name). The brand-name on this radio is probably what a USA company put on it.
: What should I check? What is the secret to getting the main board out to replace the electrolytic capacitors?
:
:Thanks,
:
:Dave
Ahhh-so.....looks likee you find yourself "one honnable" Japonie receiver. Unfortunately…with it not workee..so…you think maybe that it be “numbah ten”
As an initial evaluative test of the RF stage , refer to my two magenta square mark ups. Take one wire or 5 or 6 clip terminated test leads and daisy chain them to approximate extended car antenna length , with one clip affixed to the left magenta square mark up and the other end connected to an insulative "sky hook" above. Make an evaluation on a weaker received station and then move the "pseudo" antenna over to the second magenta square where you are then bypassing the RF station...does reception improve at that input. If so, the RF stage definitely needs some investigation.
PLUS, you mentioned R11 being clipped out of circuit and the set having poor performance, so someone before must have experienced some degree of performance alteration with it being left out of circuit.
That said, look at the working schema mark-up attached and note that the unit is utilizing a common base RF amplifier in its front end. Its base bias is being derived from the 4.7 and 33k voltage divider bridge, working in conjunction with the counterpoise voltage fed in from the AGC / AVC buss that I have marked up with the green square signal path.
Its origin is back at the high level I.F. RF present on the collector circuit of the 3rd F.M. I.F. amplifier stage where a light sampling of that signal is stripped off with the 10 pf C69capacitor at the red referenced area, it then flows down to the 1S446 diode ....1st generation "geranium", like the 1N34....where the RF samples negative nodes are stripped off by shunting them to ground. That then leaves all of the + nodes to be integrated and smoothed down to pure DC with the C4-- 10 ufd cap and its companion .047 ufd RF decoupling capacitor C60. That created DC level, that is in proportion to the overall amplified RF level, is then fed on to the left and then up to that RF amp stages base junction , shifting that base biasing initially established by the R8 +R7 dividers resistor pair. It can then level out the differences in different initial RF signals coming into the receiver from its antenna.
Check out all of the components in that loop, with the initial 10 pf hardly suspect AT ALL. The diode probably has developed decreased back resistance with time due to internal electro-chemical transition at its internal junction. Take a reference reading of the developed AGC on the buss and then lift the gnd leg and sub in a new 1N34 diode there [ ..a la Radio Shackamus part #276-1123 , if you don’t have one around].... and see if there might be a decided difference in developed AGC bias. Then… be sure that electrolytic C4 has not diminished its capacitive value down to ~ .1 ufd after ~40 years. Don’t suspect any problem with companion C60, with it probably being a disc ceramic unit, but lift one leg and initiate a resistive leakage test on it.
Schematic reference thumbnail :
Lastly, the RF amp xstr is even suspect also, if none of the above pan out, you might swap it out with the mixer and see if the set still works OK as that particular function is more critical on that xstr than the RF stage, if it performs n that slot it, certainly will work as the RF.
73's de Edd
:Hello All,
: I hope that a 1968 radio isn't too new for the forum. This radio is in SAMS AR-57, which I don't own. The output from the tuner is weak on FM and there is no output on AM. Someone cut the lead on one of the resistors (4.7K) on the FM board. If it's re-connected FM becomes even weaker.
: The schematic that's inside one of the covers is not so good. I cannot find the FM board or that resistor on it. If it's on that schematic I can't find it.
: This radio has the brand name "Cartrol-Aire" on it and models FA 205 and FA 205EX listed on the schematic and on the label with the model number. Components say TEN on them inside. This has to be a TEN (Japanese Brand Name). The brand-name on this radio is probably what a USA company put on it.
: What should I check? What is the secret to getting the main board out to replace the electrolytic capacitors?
:
:Thanks,
:
:Dave
I just notice your reply. Sorry it took so long to for me to find it. The e-mail address I used was my other e-mail address. I have a few of them. I canceled borg, I still have dreamscape and the one I used here is my own domain name.
I'll let everyone what I have found out about the TEN car radio.
Thanks Very Much,
Dave
:
:
::SRC=http://img247.imageshack.us/img247/8241/kilroyfinaldy4.png>
:
:Ahhh-so.....looks likee you find yourself "one honnable" Japonie receiver. Unfortunately…with it not workee..so…you think maybe that it be “numbah ten”
:
:
:As an initial evaluative test of the RF stage , refer to my two magenta square mark ups. Take one wire or 5 or 6 clip terminated test leads and daisy chain them to approximate extended car antenna length , with one clip affixed to the left magenta square mark up and the other end connected to an insulative "sky hook" above. Make an evaluation on a weaker received station and then move the "pseudo" antenna over to the second magenta square where you are then bypassing the RF station...does reception improve at that input. If so, the RF stage definitely needs some investigation.
:
:
:
:PLUS, you mentioned R11 being clipped out of circuit and the set having poor performance, so someone before must have experienced some degree of performance alteration with it being left out of circuit.
:
:That said, look at the working schema mark-up attached and note that the unit is utilizing a common base RF amplifier in its front end. Its base bias is being derived from the 4.7 and 33k voltage divider bridge, working in conjunction with the counterpoise voltage fed in from the AGC / AVC buss that I have marked up with the green square signal path.
:
:Its origin is back at the high level I.F. RF present on the collector circuit of the 3rd F.M. I.F. amplifier stage where a light sampling of that signal is stripped off with the 10 pf C69capacitor at the red referenced area, it then flows down to the 1S446 diode ....1st generation "geranium", like the 1N34....where the RF samples negative nodes are stripped off by shunting them to ground. That then leaves all of the + nodes to be integrated and smoothed down to pure DC with the C4-- 10 ufd cap and its companion .047 ufd RF decoupling capacitor C60. That created DC level, that is in proportion to the overall amplified RF level, is then fed on to the left and then up to that RF amp stages base junction , shifting that base biasing initially established by the R8 +R7 dividers resistor pair. It can then level out the differences in different initial RF signals coming into the receiver from its antenna.
:
:
:
:Check out all of the components in that loop, with the initial 10 pf hardly suspect AT ALL. The diode probably has developed decreased back resistance with time due to internal electro-chemical transition at its internal junction. Take a reference reading of the developed AGC on the buss and then lift the gnd leg and sub in a new 1N34 diode there [ ..a la Radio Shackamus part #276-1123 , if you don’t have one around].... and see if there might be a decided difference in developed AGC bias. Then… be sure that electrolytic C4 has not diminished its capacitive value down to ~ .1 ufd after ~40 years. Don’t suspect any problem with companion C60, with it probably being a disc ceramic unit, but lift one leg and initiate a resistive leakage test on it.
:
:
:
:Schematic reference thumbnail :
:
:
:
:
:Lastly, the RF amp xstr is even suspect also, if none of the above pan out, you might swap it out with the mixer and see if the set still works OK as that particular function is more critical on that xstr than the RF stage, if it performs n that slot it, certainly will work as the RF.
:
:
:
:
:73's de Edd
:
:
:
:
:
:
:
:
:
:
:
:
:
::Hello All,
:: I hope that a 1968 radio isn't too new for the forum. This radio is in SAMS AR-57, which I don't own. The output from the tuner is weak on FM and there is no output on AM. Someone cut the lead on one of the resistors (4.7K) on the FM board. If it's re-connected FM becomes even weaker.
:: The schematic that's inside one of the covers is not so good. I cannot find the FM board or that resistor on it. If it's on that schematic I can't find it.
:: This radio has the brand name "Cartrol-Aire" on it and models FA 205 and FA 205EX listed on the schematic and on the label with the model number. Components say TEN on them inside. This has to be a TEN (Japanese Brand Name). The brand-name on this radio is probably what a USA company put on it.
:: What should I check? What is the secret to getting the main board out to replace the electrolytic capacitors?
::
::Thanks,
::
::Dave
I still have weak audio from the tuner. The main amp seems to work except now I'm getting a lot of loud annoying rumble from the speaker. Sometimes I can stop it by adjusting the volume and tone control but most of the time the radio is just a "buzzer". I don't know what to look at next. If I disconnect the center tap of L29 and connect it to the chassis instead of ground, I can still hear the weak audio through the speaker but the oscillation is gone. What should I check to stop that terrible noise? This could also be a clue as to why the audio is so weak. There has got to be a faulty component somewhere between the tuner and the amplifier. But I am at a loss to find it.
Thanks,
Dave
:Edd,
: I just notice your reply. Sorry it took so long to for me to find it. The e-mail address I used was my other e-mail address. I have a few of them. I canceled borg, I still have dreamscape and the one I used here is my own domain name.
:
:I'll let everyone what I have found out about the TEN car radio.
:
:Thanks Very Much,
:
:Dave
::
::
::::SRC=http://img247.imageshack.us/img247/8241/kilroyfinaldy4.png>
::
::Ahhh-so.....looks likee you find yourself "one honnable" Japonie receiver. Unfortunately…with it not workee..so…you think maybe that it be “numbah ten”
::
::
::As an initial evaluative test of the RF stage , refer to my two magenta square mark ups. Take one wire or 5 or 6 clip terminated test leads and daisy chain them to approximate extended car antenna length , with one clip affixed to the left magenta square mark up and the other end connected to an insulative "sky hook" above. Make an evaluation on a weaker received station and then move the "pseudo" antenna over to the second magenta square where you are then bypassing the RF station...does reception improve at that input. If so, the RF stage definitely needs some investigation.
::
::
::
::PLUS, you mentioned R11 being clipped out of circuit and the set having poor performance, so someone before must have experienced some degree of performance alteration with it being left out of circuit.
::
::That said, look at the working schema mark-up attached and note that the unit is utilizing a common base RF amplifier in its front end. Its base bias is being derived from the 4.7 and 33k voltage divider bridge, working in conjunction with the counterpoise voltage fed in from the AGC / AVC buss that I have marked up with the green square signal path.
::
::Its origin is back at the high level I.F. RF present on the collector circuit of the 3rd F.M. I.F. amplifier stage where a light sampling of that signal is stripped off with the 10 pf C69capacitor at the red referenced area, it then flows down to the 1S446 diode ....1st generation "geranium", like the 1N34....where the RF samples negative nodes are stripped off by shunting them to ground. That then leaves all of the + nodes to be integrated and smoothed down to pure DC with the C4-- 10 ufd cap and its companion .047 ufd RF decoupling capacitor C60. That created DC level, that is in proportion to the overall amplified RF level, is then fed on to the left and then up to that RF amp stages base junction , shifting that base biasing initially established by the R8 +R7 dividers resistor pair. It can then level out the differences in different initial RF signals coming into the receiver from its antenna.
::
::
::
::Check out all of the components in that loop, with the initial 10 pf hardly suspect AT ALL. The diode probably has developed decreased back resistance with time due to internal electro-chemical transition at its internal junction. Take a reference reading of the developed AGC on the buss and then lift the gnd leg and sub in a new 1N34 diode there [ ..a la Radio Shackamus part #276-1123 , if you don’t have one around].... and see if there might be a decided difference in developed AGC bias. Then… be sure that electrolytic C4 has not diminished its capacitive value down to ~ .1 ufd after ~40 years. Don’t suspect any problem with companion C60, with it probably being a disc ceramic unit, but lift one leg and initiate a resistive leakage test on it.
::
::
::
::Schematic reference thumbnail :
::
::
::
::
::Lastly, the RF amp xstr is even suspect also, if none of the above pan out, you might swap it out with the mixer and see if the set still works OK as that particular function is more critical on that xstr than the RF stage, if it performs n that slot it, certainly will work as the RF.
::
::
::
::
::73's de Edd
::
::
::
::
::
::
::
::
::
::
::
::
::
:::Hello All,
::: I hope that a 1968 radio isn't too new for the forum. This radio is in SAMS AR-57, which I don't own. The output from the tuner is weak on FM and there is no output on AM. Someone cut the lead on one of the resistors (4.7K) on the FM board. If it's re-connected FM becomes even weaker.
::: The schematic that's inside one of the covers is not so good. I cannot find the FM board or that resistor on it. If it's on that schematic I can't find it.
::: This radio has the brand name "Cartrol-Aire" on it and models FA 205 and FA 205EX listed on the schematic and on the label with the model number. Components say TEN on them inside. This has to be a TEN (Japanese Brand Name). The brand-name on this radio is probably what a USA company put on it.
::: What should I check? What is the secret to getting the main board out to replace the electrolytic capacitors?
:::
:::Thanks,
:::
:::Dave