Zenith 7H820

9/7/2012 8:15:19 AMfrank goddard

Working on a Zenith 7H820. A quick glance at the schematic shows dodgy mains connection to the FM antenna. Even with the cap in series with the antenna terminal and coil L7 I am wary of using this connection. Even with the chassis at neutral. Any ideas how I might reconnect this FM side to overcome a possible danger.

Many thanks.

Frank Goddard. Doncaster England.

9/7/2012 8:58:36 AMLou

Frank:

Maybe I have missed something but I do not see any connection to the mains from the FM antenna on the schematic.

Lou

:Working on a Zenith 7H820. A quick glance at the schematic shows dodgy mains connection to the FM antenna. Even with the cap in series with the antenna terminal and coil L7 I am wary of using this connection. Even with the chassis at neutral. Any ideas how I might reconnect this FM side to overcome a possible danger.
:
:Many thanks.
:
:Frank Goddard. Doncaster England.
:

9/7/2012 9:49:45 AMLewis L.

:Frank:
:
:Maybe I have missed something but I do not see any connection to the mains from the FM antenna on the schematic.
:
:Lou
:
::Working on a Zenith 7H820. A quick glance at the schematic shows dodgy mains connection to the FM antenna. Even with the cap in series with the antenna terminal and coil L7 I am wary of using this connection. Even with the chassis at neutral. Any ideas how I might reconnect this FM side to overcome a possible danger.
::
::Many thanks.
::
::Frank Goddard. Doncaster England.

Frank:
The lead to the mains is connected through a small capacitor, which presents a high impedance to the mains frequency of, in your case, 50 Hz, and permits the higher FM frequencies to pass. However, I perfer to make a dipole out of flat 300 Ohm lead in cable, and use that, forgetting the mains antenna completely, for the computer, TV converters and other modern things in the house make the mains have more interference than in the days when they were usefus as an antenna. I would insualate the mains lead and forget it. You can easily find out how to make a FM antenna out of twin lead numerous places on the internet.
Lewis L.
Atlanta, GA, USA
::
:
:

9/7/2012 1:12:24 PMfrank goddard

::Frank:
::
::Maybe I have missed something but I do not see any connection to the mains from the FM antenna on the schematic.
::
::Lou
::
:::Working on a Zenith 7H820. A quick glance at the schematic shows dodgy mains connection to the FM antenna. Even with the cap in series with the antenna terminal and coil L7 I am wary of using this connection. Even with the chassis at neutral. Any ideas how I might reconnect this FM side to overcome a possible danger.
:::
:::Many thanks.
:::
:::Frank Goddard. Doncaster England.
:
:Frank:
:The lead to the mains is connected through a small capacitor, which presents a high impedance to the mains frequency of, in your case, 50 Hz, and permits the higher FM frequencies to pass. However, I perfer to make a dipole out of flat 300 Ohm lead in cable, and use that, forgetting the mains antenna completely, for the computer, TV converters and other modern things in the house make the mains have more interference than in the days when they were usefus as an antenna. I would insualate the mains lead and forget it. You can easily find out how to make a FM antenna out of twin lead numerous places on the internet.
:Lewis L.
:Atlanta, GA, USA
:::
::
::
:Lewis

So that explains it perfectly. As you say better to disconnect this filter cap and use a dipole. Can get them from Radio Shack etc for a few pennies. Gratefull for your input.

Lou. Sorry I did not explain myself too clearly. Thanks anyway for your response

Frank
:

9/7/2012 2:52:58 PMLewis L.

:::Frank:
:::
:::Maybe I have missed something but I do not see any connection to the mains from the FM antenna on the schematic.
:::
:::Lou
:::
::::Working on a Zenith 7H820. A quick glance at the schematic shows dodgy mains connection to the FM antenna. Even with the cap in series with the antenna terminal and coil L7 I am wary of using this connection. Even with the chassis at neutral. Any ideas how I might reconnect this FM side to overcome a possible danger.
::::
::::Many thanks.
::::
::::Frank Goddard. Doncaster England.
::
::Frank:
::The lead to the mains is connected through a small capacitor, which presents a high impedance to the mains frequency of, in your case, 50 Hz, and permits the higher FM frequencies to pass. However, I perfer to make a dipole out of flat 300 Ohm lead in cable, and use that, forgetting the mains antenna completely, for the computer, TV converters and other modern things in the house make the mains have more interference than in the days when they were usefus as an antenna. I would insualate the mains lead and forget it. You can easily find out how to make a FM antenna out of twin lead numerous places on the internet.
::Lewis L.
::Atlanta, GA, USA
::::
:::
:::
::Lewis
:
:So that explains it perfectly. As you say better to disconnect this filter cap and use a dipole. Can get them from Radio Shack etc for a few pennies. Gratefull for your input.
:
:Lou. Sorry I did not explain myself too clearly. Thanks anyway for your response
:
:
:
:Frank

Frank:
Before you spend any Pence at all, try connecting a couple of wires, say about two meters long, to the antenna terminals, and orient them in a line perpendicular to the direction of the station (if known, otherwise for the best reception of the signal). Where I live, the city of Atlanta is about twenty miles West of me, with a giant airport on the South side of the city, so most of the tall FM and TV towers are to the Northwest of me, from, say, twenty to forty miles away, and I get more FM stations than I know what to do with with just lamp cord wire remnants.
Lewis
::
:
:

9/8/2012 7:11:08 AMfrank goddard

::::Frank:
::::
::::Maybe I have missed something but I do not see any connection to the mains from the FM antenna on the schematic.
::::
::::Lou
::::
:::::Working on a Zenith 7H820. A quick glance at the schematic shows dodgy mains connection to the FM antenna. Even with the cap in series with the antenna terminal and coil L7 I am wary of using this connection. Even with the chassis at neutral. Any ideas how I might reconnect this FM side to overcome a possible danger.
:::::
:::::Many thanks.
:::::
:::::Frank Goddard. Doncaster England.
:::
:::Frank:
:::The lead to the mains is connected through a small capacitor, which presents a high impedance to the mains frequency of, in your case, 50 Hz, and permits the higher FM frequencies to pass. However, I perfer to make a dipole out of flat 300 Ohm lead in cable, and use that, forgetting the mains antenna completely, for the computer, TV converters and other modern things in the house make the mains have more interference than in the days when they were usefus as an antenna. I would insualate the mains lead and forget it. You can easily find out how to make a FM antenna out of twin lead numerous places on the internet.
:::Lewis L.
:::Atlanta, GA, USA
:::::
::::
::::
:::Lewis
::
::So that explains it perfectly. As you say better to disconnect this filter cap and use a dipole. Can get them from Radio Shack etc for a few pennies. Gratefull for your input.
::
::Lou. Sorry I did not explain myself too clearly. Thanks anyway for your response
::
::
::
::Frank
:
:Frank:
:Before you spend any Pence at all, try connecting a couple of wires, say about two meters long, to the antenna terminals, and orient them in a line perpendicular to the direction of the station (if known, otherwise for the best reception of the signal). Where I live, the city of Atlanta is about twenty miles West of me, with a giant airport on the South side of the city, so most of the tall FM and TV towers are to the Northwest of me, from, say, twenty to forty miles away, and I get more FM stations than I know what to do with with just lamp cord wire remnants.
:Lewis
:::
::
:Lewis

Fixed as you suggested a couple of 2 mtr lengths of flex to each FM terminal. Reception great. I reduced this to about 4 feet to each leg and reception the same. About 35 stations here 30 miles south of York and 180 miles north of london. Many thanks

Frank:
:
:

9/8/2012 7:39:32 AMLou

Frank:

What I have seen on later model Zeniths is that they use a metal clip on the outside of the back cover of the radio, and the clip surrounds the 2 wires of the AC line cord, with a cardboard insulator in between. Then the clip is tied to one terminal of the FM antenna screws. This results in using the AC power line like an antenna without using a capacitor. In fact you are making a capacitor using this clip and insulator. It also helps to hold the line cord in place, using the antenna screw as a support.

Lou:
:
:
:
:::::Frank:
:::::
:::::Maybe I have missed something but I do not see any connection to the mains from the FM antenna on the schematic.
:::::
:::::Lou
:::::
::::::Working on a Zenith 7H820. A quick glance at the schematic shows dodgy mains connection to the FM antenna. Even with the cap in series with the antenna terminal and coil L7 I am wary of using this connection. Even with the chassis at neutral. Any ideas how I might reconnect this FM side to overcome a possible danger.
::::::
::::::Many thanks.
::::::
::::::Frank Goddard. Doncaster England.
::::
::::Frank:
::::The lead to the mains is connected through a small capacitor, which presents a high impedance to the mains frequency of, in your case, 50 Hz, and permits the higher FM frequencies to pass. However, I perfer to make a dipole out of flat 300 Ohm lead in cable, and use that, forgetting the mains antenna completely, for the computer, TV converters and other modern things in the house make the mains have more interference than in the days when they were usefus as an antenna. I would insualate the mains lead and forget it. You can easily find out how to make a FM antenna out of twin lead numerous places on the internet.
::::Lewis L.
::::Atlanta, GA, USA
::::::
:::::
:::::
::::Lewis
:::
:::So that explains it perfectly. As you say better to disconnect this filter cap and use a dipole. Can get them from Radio Shack etc for a few pennies. Gratefull for your input.
:::
:::Lou. Sorry I did not explain myself too clearly. Thanks anyway for your response
:::
:::
:::
:::Frank
::
::Frank:
::Before you spend any Pence at all, try connecting a couple of wires, say about two meters long, to the antenna terminals, and orient them in a line perpendicular to the direction of the station (if known, otherwise for the best reception of the signal). Where I live, the city of Atlanta is about twenty miles West of me, with a giant airport on the South side of the city, so most of the tall FM and TV towers are to the Northwest of me, from, say, twenty to forty miles away, and I get more FM stations than I know what to do with with just lamp cord wire remnants.
::Lewis
::::
:::
::Lewis
:
:Fixed as you suggested a couple of 2 mtr lengths of flex to each FM terminal. Reception great. I reduced this to about 4 feet to each leg and reception the same. About 35 stations here 30 miles south of York and 180 miles north of london. Many thanks
:
:Frank:
::
::
:
:

9/9/2012 4:09:54 AMfrank goddard

Lou

I have noticed this myself too. In fact just this arrangement is applied to a Granco that is half finished here on my workbench. An ingeneouse method. It amazes me that there were such great and yet simple ideas back then that just seem so obviouse now with hindsight.

Frank

:Frank:
:
:What I have seen on later model Zeniths is that they use a metal clip on the outside of the back cover of the radio, and the clip surrounds the 2 wires of the AC line cord, with a cardboard insulator in between. Then the clip is tied to one terminal of the FM antenna screws. This results in using the AC power line like an antenna without using a capacitor. In fact you are making a capacitor using this clip and insulator. It also helps to hold the line cord in place, using the antenna screw as a support.
:
:Lou:
::
::
::
::::::Frank:
::::::
::::::Maybe I have missed something but I do not see any connection to the mains from the FM antenna on the schematic.
::::::
::::::Lou
::::::
:::::::Working on a Zenith 7H820. A quick glance at the schematic shows dodgy mains connection to the FM antenna. Even with the cap in series with the antenna terminal and coil L7 I am wary of using this connection. Even with the chassis at neutral. Any ideas how I might reconnect this FM side to overcome a possible danger.
:::::::
:::::::Many thanks.
:::::::
:::::::Frank Goddard. Doncaster England.
:::::
:::::Frank:
:::::The lead to the mains is connected through a small capacitor, which presents a high impedance to the mains frequency of, in your case, 50 Hz, and permits the higher FM frequencies to pass. However, I perfer to make a dipole out of flat 300 Ohm lead in cable, and use that, forgetting the mains antenna completely, for the computer, TV converters and other modern things in the house make the mains have more interference than in the days when they were usefus as an antenna. I would insualate the mains lead and forget it. You can easily find out how to make a FM antenna out of twin lead numerous places on the internet.
:::::Lewis L.
:::::Atlanta, GA, USA
:::::::
::::::
::::::
:::::Lewis
::::
::::So that explains it perfectly. As you say better to disconnect this filter cap and use a dipole. Can get them from Radio Shack etc for a few pennies. Gratefull for your input.
::::
::::Lou. Sorry I did not explain myself too clearly. Thanks anyway for your response
::::
::::
::::
::::Frank
:::
:::Frank:
:::Before you spend any Pence at all, try connecting a couple of wires, say about two meters long, to the antenna terminals, and orient them in a line perpendicular to the direction of the station (if known, otherwise for the best reception of the signal). Where I live, the city of Atlanta is about twenty miles West of me, with a giant airport on the South side of the city, so most of the tall FM and TV towers are to the Northwest of me, from, say, twenty to forty miles away, and I get more FM stations than I know what to do with with just lamp cord wire remnants.
:::Lewis
:::::
::::
:::Lewis
::
::Fixed as you suggested a couple of 2 mtr lengths of flex to each FM terminal. Reception great. I reduced this to about 4 feet to each leg and reception the same. About 35 stations here 30 miles south of York and 180 miles north of london. Many thanks
::
::Frank:
:::
:::
::
::
:
:

9/9/2012 7:31:36 AMLewis L.

:Frank:
:
:What I have seen on later model Zeniths is that they use a metal clip on the outside of the back cover of the radio, and the clip surrounds the 2 wires of the AC line cord, with a cardboard insulator in between. Then the clip is tied to one terminal of the FM antenna screws. This results in using the AC power line like an antenna without using a capacitor. In fact you are making a capacitor using this clip and insulator. It also helps to hold the line cord in place, using the antenna screw as a support.
:
:Lou:
::
::
::
::::::Frank:
::::::
::::::Maybe I have missed something but I do not see any connection to the mains from the FM antenna on the schematic.
::::::
::::::Lou
::::::
:::::::Working on a Zenith 7H820. A quick glance at the schematic shows dodgy mains connection to the FM antenna. Even with the cap in series with the antenna terminal and coil L7 I am wary of using this connection. Even with the chassis at neutral. Any ideas how I might reconnect this FM side to overcome a possible danger.
:::::::
:::::::Many thanks.
:::::::
:::::::Frank Goddard. Doncaster England.
:::::
:::::Frank:
:::::The lead to the mains is connected through a small capacitor, which presents a high impedance to the mains frequency of, in your case, 50 Hz, and permits the higher FM frequencies to pass. However, I perfer to make a dipole out of flat 300 Ohm lead in cable, and use that, forgetting the mains antenna completely, for the computer, TV converters and other modern things in the house make the mains have more interference than in the days when they were usefus as an antenna. I would insualate the mains lead and forget it. You can easily find out how to make a FM antenna out of twin lead numerous places on the internet.
:::::Lewis L.
:::::Atlanta, GA, USA
:::::::
::::::
::::::
:::::Lewis
::::
::::So that explains it perfectly. As you say better to disconnect this filter cap and use a dipole. Can get them from Radio Shack etc for a few pennies. Gratefull for your input.
::::
::::Lou. Sorry I did not explain myself too clearly. Thanks anyway for your response
::::
::::
::::
::::Frank
:::
:::Frank:
:::Before you spend any Pence at all, try connecting a couple of wires, say about two meters long, to the antenna terminals, and orient them in a line perpendicular to the direction of the station (if known, otherwise for the best reception of the signal). Where I live, the city of Atlanta is about twenty miles West of me, with a giant airport on the South side of the city, so most of the tall FM and TV towers are to the Northwest of me, from, say, twenty to forty miles away, and I get more FM stations than I know what to do with with just lamp cord wire remnants.
:::Lewis
:::::
::::
:::Lewis
::
::Fixed as you suggested a couple of 2 mtr lengths of flex to each FM terminal. Reception great. I reduced this to about 4 feet to each leg and reception the same. About 35 stations here 30 miles south of York and 180 miles north of london. Many thanks
::
::Frank:
:::
:::
Frank:
How close to Leeds would you be? I have toured the British Isles, Only the big on as far North as Leeds, but South from London to the sea, visiting pubs and talking to people. Wonderful people you have over there, I shall have to visit again some time.
Lewis
::
:
:

9/10/2012 4:48:05 AMfrank goddard

::Frank:
::
::What I have seen on later model Zeniths is that they use a metal clip on the outside of the back cover of the radio, and the clip surrounds the 2 wires of the AC line cord, with a cardboard insulator in between. Then the clip is tied to one terminal of the FM antenna screws. This results in using the AC power line like an antenna without using a capacitor. In fact you are making a capacitor using this clip and insulator. It also helps to hold the line cord in place, using the antenna screw as a support.
::
::Lou:
:::
:::
:::
:::::::Frank:
:::::::
:::::::Maybe I have missed something but I do not see any connection to the mains from the FM antenna on the schematic.
:::::::
:::::::Lou
:::::::
::::::::Working on a Zenith 7H820. A quick glance at the schematic shows dodgy mains connection to the FM antenna. Even with the cap in series with the antenna terminal and coil L7 I am wary of using this connection. Even with the chassis at neutral. Any ideas how I might reconnect this FM side to overcome a possible danger.
::::::::
::::::::Many thanks.
::::::::
::::::::Frank Goddard. Doncaster England.
::::::
::::::Frank:
::::::The lead to the mains is connected through a small capacitor, which presents a high impedance to the mains frequency of, in your case, 50 Hz, and permits the higher FM frequencies to pass. However, I perfer to make a dipole out of flat 300 Ohm lead in cable, and use that, forgetting the mains antenna completely, for the computer, TV converters and other modern things in the house make the mains have more interference than in the days when they were usefus as an antenna. I would insualate the mains lead and forget it. You can easily find out how to make a FM antenna out of twin lead numerous places on the internet.
::::::Lewis L.
::::::Atlanta, GA, USA
::::::::
:::::::
:::::::
::::::Lewis
:::::
:::::So that explains it perfectly. As you say better to disconnect this filter cap and use a dipole. Can get them from Radio Shack etc for a few pennies. Gratefull for your input.
:::::
:::::Lou. Sorry I did not explain myself too clearly. Thanks anyway for your response
:::::
:::::
:::::
:::::Frank
::::
::::Frank:
::::Before you spend any Pence at all, try connecting a couple of wires, say about two meters long, to the antenna terminals, and orient them in a line perpendicular to the direction of the station (if known, otherwise for the best reception of the signal). Where I live, the city of Atlanta is about twenty miles West of me, with a giant airport on the South side of the city, so most of the tall FM and TV towers are to the Northwest of me, from, say, twenty to forty miles away, and I get more FM stations than I know what to do with with just lamp cord wire remnants.
::::Lewis
::::::
:::::
::::Lewis
:::
:::Fixed as you suggested a couple of 2 mtr lengths of flex to each FM terminal. Reception great. I reduced this to about 4 feet to each leg and reception the same. About 35 stations here 30 miles south of York and 180 miles north of london. Many thanks
:::
:::Frank:
::::
::::
:Frank:
:How close to Leeds would you be? I have toured the British Isles, Only the big on as far North as Leeds, but South from London to the sea, visiting pubs and talking to people. Wonderful people you have over there, I shall have to visit again some time.
:Lewis
:::
::
::Lewis

http://www.barnburghandharlington.co.uk/index.html This link is to our village web site. I live about 30 minutes south of leeds in a small anglo saxon village called barnburgh.

If you ever get this way again be sure to contact me before hand. Nearby to Leeds is the CIA listening post. Google Menwith Hill to find all about it. It is the next most important listening site next to the one in VA. Lots of your fellow countrymen there.

Frank
:
:

9/10/2012 4:48:08 AMfrank goddard

::Frank:
::
::What I have seen on later model Zeniths is that they use a metal clip on the outside of the back cover of the radio, and the clip surrounds the 2 wires of the AC line cord, with a cardboard insulator in between. Then the clip is tied to one terminal of the FM antenna screws. This results in using the AC power line like an antenna without using a capacitor. In fact you are making a capacitor using this clip and insulator. It also helps to hold the line cord in place, using the antenna screw as a support.
::
::Lou:
:::
:::
:::
:::::::Frank:
:::::::
:::::::Maybe I have missed something but I do not see any connection to the mains from the FM antenna on the schematic.
:::::::
:::::::Lou
:::::::
::::::::Working on a Zenith 7H820. A quick glance at the schematic shows dodgy mains connection to the FM antenna. Even with the cap in series with the antenna terminal and coil L7 I am wary of using this connection. Even with the chassis at neutral. Any ideas how I might reconnect this FM side to overcome a possible danger.
::::::::
::::::::Many thanks.
::::::::
::::::::Frank Goddard. Doncaster England.
::::::
::::::Frank:
::::::The lead to the mains is connected through a small capacitor, which presents a high impedance to the mains frequency of, in your case, 50 Hz, and permits the higher FM frequencies to pass. However, I perfer to make a dipole out of flat 300 Ohm lead in cable, and use that, forgetting the mains antenna completely, for the computer, TV converters and other modern things in the house make the mains have more interference than in the days when they were usefus as an antenna. I would insualate the mains lead and forget it. You can easily find out how to make a FM antenna out of twin lead numerous places on the internet.
::::::Lewis L.
::::::Atlanta, GA, USA
::::::::
:::::::
:::::::
::::::Lewis
:::::
:::::So that explains it perfectly. As you say better to disconnect this filter cap and use a dipole. Can get them from Radio Shack etc for a few pennies. Gratefull for your input.
:::::
:::::Lou. Sorry I did not explain myself too clearly. Thanks anyway for your response
:::::
:::::
:::::
:::::Frank
::::
::::Frank:
::::Before you spend any Pence at all, try connecting a couple of wires, say about two meters long, to the antenna terminals, and orient them in a line perpendicular to the direction of the station (if known, otherwise for the best reception of the signal). Where I live, the city of Atlanta is about twenty miles West of me, with a giant airport on the South side of the city, so most of the tall FM and TV towers are to the Northwest of me, from, say, twenty to forty miles away, and I get more FM stations than I know what to do with with just lamp cord wire remnants.
::::Lewis
::::::
:::::
::::Lewis
:::
:::Fixed as you suggested a couple of 2 mtr lengths of flex to each FM terminal. Reception great. I reduced this to about 4 feet to each leg and reception the same. About 35 stations here 30 miles south of York and 180 miles north of london. Many thanks
:::
:::Frank:
::::
::::
:Frank:
:How close to Leeds would you be? I have toured the British Isles, Only the big on as far North as Leeds, but South from London to the sea, visiting pubs and talking to people. Wonderful people you have over there, I shall have to visit again some time.
:Lewis
:::
::
::Lewis

http://www.barnburghandharlington.co.uk/index.html This link is to our village web site. I live about 30 minutes south of leeds in a small anglo saxon village called barnburgh.

If you ever get this way again be sure to contact me before hand. Nearby to Leeds is the CIA listening post. Google Menwith Hill to find all about it. It is the next most important listening site next to the one in VA. Lots of your fellow countrymen there.

Frank
:
:

9/10/2012 12:28:07 PMFrank H

Yes, Menwith Hill has quite a few good toys. Worked in the defense industry once upon a time and we had some hardware there.

Have also spent time in Leeds - most enjoyable.

Frank in Indiana

:http://www.barnburghandharlington.co.uk/index.html This link is to our village web site. I live about 30 minutes south of leeds in a small anglo saxon village called barnburgh.
:
:If you ever get this way again be sure to contact me before hand. Nearby to Leeds is the CIA listening post. Google Menwith Hill to find all about it. It is the next most important listening site next to the one in VA. Lots of your fellow countrymen there.
:
:Frank
::
::
:
: