UK Vintage Radio Repair and Restoration Powered By Google Custom Search Vintage Radio Service Data

Go Back   UK Vintage Radio Repair and Restoration Discussion Forum > Offered and Wanted Messages > Sets, Parts and Service Information Offered (private sellers only, exact price required, no swaps)

Notices

Sets, Parts and Service Information Offered (private sellers only, exact price required, no swaps) You may announce components or sets for sale or offered free here. Private collectors only - no traders. You must include an exact price. No swaps.

Reply
 
Thread Tools
Old 1st Apr 2019, 2:02 pm   #1
KeithsTV
Nonode
 
KeithsTV's Avatar
 
Join Date: Aug 2007
Location: South Bradford, West Yorkshire, UK.
Posts: 2,202
Default US channel 3/4 modulators FOC

I have a number of modulators surplus to requirements. These are US modulators with the RF output on either US channel 3 or 4. They use the Motorola MC44BC375U modulator IC which, according to the data sheet can have the FM sound output as either 4.5MHz or 5.5MHz.

I have no data on the connections but it should be possible to work them out from the data sheet.

These are free to anyone who can give them a home. I can take them to Golborne on Sunday, NVCF or Mikey405s swapmeet in May. Alternatively postage at cost.

Keith
Attached Thumbnails
Click image for larger version

Name:	modulators.jpg
Views:	113
Size:	55.9 KB
ID:	180695  
KeithsTV is offline   Reply With Quote
Old 1st Apr 2019, 4:27 pm   #2
chriswood1900
Heptode
 
Join Date: Jan 2007
Location: Bristol, UK.
Posts: 692
Default Re: US channel 3/4 modulators FOC

Hi Keith
I would like these please, I will probably be at Mikeys and will be NVCF so should be able to pick them up then.
Thanks
Chris
chriswood1900 is offline   Reply With Quote
Old 1st Apr 2019, 5:34 pm   #3
KeithsTV
Nonode
 
KeithsTV's Avatar
 
Join Date: Aug 2007
Location: South Bradford, West Yorkshire, UK.
Posts: 2,202
Default Re: US channel 3/4 modulators FOC

No problem Chris

How many would you like as I have around 30!

Keith
KeithsTV is offline   Reply With Quote
Old 1st Apr 2019, 6:39 pm   #4
mobileauto
Tetrode
 
Join Date: Sep 2012
Location: Golborne, near Warrington, UK
Posts: 50
Default Re: US channel 3/4 modulators FOC

Hello Keith could I put my name down for three if there is any left I will be at golborne on sunday Regards Dave.
mobileauto is offline   Reply With Quote
Old 1st Apr 2019, 9:17 pm   #5
chriswood1900
Heptode
 
Join Date: Jan 2007
Location: Bristol, UK.
Posts: 692
Default Re: US channel 3/4 modulators FOC

Hi Keith, somehow I thought it was a a couple, if you have enough I would like 4 please.
Chris
chriswood1900 is offline   Reply With Quote
Old 1st Apr 2019, 9:31 pm   #6
dragonser
Hexode
 
dragonser's Avatar
 
Join Date: Aug 2009
Location: Carshalton, Surrey, UK.
Posts: 444
Default Re: US channel 3/4 modulators FOC

Hi,
that is just what I need ! These would be much appreciated. If I could have three that would be great. They would need to be posted to me.
__________________
Regards Peter B
dragonser is offline   Reply With Quote
Old 1st Apr 2019, 11:45 pm   #7
KeithsTV
Nonode
 
KeithsTV's Avatar
 
Join Date: Aug 2007
Location: South Bradford, West Yorkshire, UK.
Posts: 2,202
Default Re: US channel 3/4 modulators FOC

Dave. I'll see you at Golborne on Sunday. I'll be wearing my avatar badge. I'll also be giving the talk in the side room.

Chris. I've replied to your PM.

Peter. No problem PM me your address and I'll get them in the post.

Can I tempt any one else?

Keith
KeithsTV is offline   Reply With Quote
Old 2nd Apr 2019, 2:03 pm   #8
kan_turk
Pentode
 
kan_turk's Avatar
 
Join Date: Mar 2014
Location: Dublin, Ireland
Posts: 245
Default Re: US channel 3/4 modulators FOC

Hi Keith
Id like a couple or three of these please if you have them to spare - would need posting to BT36

Kindest regards
John
kan_turk is offline   Reply With Quote
Old 2nd Apr 2019, 3:52 pm   #9
KeithsTV
Nonode
 
KeithsTV's Avatar
 
Join Date: Aug 2007
Location: South Bradford, West Yorkshire, UK.
Posts: 2,202
Default Re: US channel 3/4 modulators FOC

John

PM me your address and I'll get some sent off.

I'll also bring a load to Golborne on Sunday and if there are any left I'll take them down to Solihull/NVCF.

Keith
KeithsTV is offline   Reply With Quote
Old 2nd Apr 2019, 5:55 pm   #10
winston_1
Hexode
 
Join Date: Oct 2012
Location: London, UK.
Posts: 280
Default Re: US channel 3/4 modulators FOC

PM sent.
winston_1 is offline   Reply With Quote
Old 3rd Apr 2019, 3:56 pm   #11
KeithsTV
Nonode
 
KeithsTV's Avatar
 
Join Date: Aug 2007
Location: South Bradford, West Yorkshire, UK.
Posts: 2,202
Default Re: US channel 3/4 modulators FOC

I've managed to trace out the connection details and have checked the modulators I have and all will output RF which changes channel when the channel pin is grounded. I fed one with an NTSC source from a digital camera and could see a change on the spectrum analyser and the scope so It looks as if I've got the correct pin for the video input. I haven't checked it can be displayed on a TV as I don't have a US TV!

The connection details are in the attachment.

About half of them are now accounted for so I still have a few left. I'll have them with me at Golborne this Sunday if anyone wants one or more.

Keith
Attached Files
File Type: pdf US modulator.pdf (207.4 KB, 33 views)
KeithsTV is offline   Reply With Quote
Old 13th May 2019, 8:32 am   #12
KeithsTV
Nonode
 
KeithsTV's Avatar
 
Join Date: Aug 2007
Location: South Bradford, West Yorkshire, UK.
Posts: 2,202
Default Re: US channel 3/4 modulators FOC

Having disposed of most of the modulators over the weekend some people are under the impression that the IC used in the modulators can be used in the Hedghog standards convertor. This is not the case as the IC used in the modulator, MC44BC375, is specifically intended for NTSC modulators and is completely different to the MC44BS373 used in the Hedghog.

Keith
KeithsTV is offline   Reply With Quote
Reply

Thread Tools



All times are GMT +1. The time now is 1:19 pm.


All information and advice on this forum is subject to the WARNING AND DISCLAIMER located at https://www.vintage-radio.net/rules.html.
Failure to heed this warning may result in death or serious injury to yourself and/or others.


Powered by vBulletin®
Copyright ©2000 - 2019, vBulletin Solutions, Inc.
Copyright ©2002 - 2019, Paul Stenning.