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


It is currently Jul Tue 07, 2020 1:44 am


All times are UTC [ DST ]





Post New Topic Post Reply  [ 6 posts ] 
Author Message
 Post subject: Ameco VFO-621
PostPosted: Feb Thu 15, 2018 7:07 pm 
Member

Joined: Jan Fri 27, 2017 8:41 pm
Posts: 180
Location: Springwater, NY
I've found a schematic for a version that employs two transistors and a crystal. The device I have before me looks stock and different, with only one transistor and a slightly different power supply. I'm wondering if anyone here has a schematic for an Ameco VFO-621 that only has a single transistor. Thank you!

73, Dean, NW2K


Top
 Profile  
 
 Post subject: Re: Ameco VFO-621
PostPosted: Feb Thu 15, 2018 9:42 pm 
Member
User avatar

Joined: Nov Sat 07, 2009 11:37 pm
Posts: 2436
Location: Sayreville, NJ 08872
The old version of the the VFO-621 used two transistors. They used the heterodyne principle to get to 50, 144, and 220 MHz.
The newer version, and far more common, uses only one transistor in the oscillator operating at roughly 12 to 13 MHz and doubling and tripling to get to the desired frequency range.
I have all the info for both.

_________________
Pete, WA2CWA - "A cluttered desk is a sign of genius"
http://www.classicradiomanuals.com


Top
 Profile  
 
 Post subject: Re: Ameco VFO-621
PostPosted: Feb Thu 15, 2018 9:51 pm 
Member
User avatar

Joined: Jun Sun 19, 2011 2:31 pm
Posts: 7298
Sounds like it got "cost reduced" in the later version and the original is probably quite a bit more stable. I have one but have never looked inside and it is probably also the single transistor version.

Rodger WQ9E


Top
 Profile  
 
 Post subject: Re: Ameco VFO-621
PostPosted: Feb Thu 15, 2018 10:04 pm 
Member
User avatar

Joined: Nov Sat 07, 2009 11:37 pm
Posts: 2436
Location: Sayreville, NJ 08872
Actually, the one transistor version is quite stable on the two VFO-621's I have. I had a third one, also one transistor, but sold it off years ago. The 621's are mated with the Clegg 66'er and Clegg 22'er rigs.

_________________
Pete, WA2CWA - "A cluttered desk is a sign of genius"
http://www.classicradiomanuals.com


Top
 Profile  
 
 Post subject: Re: Ameco VFO-621
PostPosted: Feb Thu 15, 2018 10:05 pm 
Member
User avatar

Joined: Nov Sat 07, 2009 11:37 pm
Posts: 2436
Location: Sayreville, NJ 08872
Dup
Must have over-clicked :mrgreen:

_________________
Pete, WA2CWA - "A cluttered desk is a sign of genius"
http://www.classicradiomanuals.com


Top
 Profile  
 
 Post subject: Re: Ameco VFO-621
PostPosted: Feb Sat 17, 2018 5:18 pm 
Member

Joined: Jan Fri 27, 2017 8:41 pm
Posts: 180
Location: Springwater, NY
Special thanks to Allen W9DZ for scanning and emailing the "one-transistor" manual (with schematic) to me. Thanks Allen!

73, Dean, NW2K


Top
 Profile  
 
Post New Topic Post Reply  [ 6 posts ]  Moderator: Sandy

All times are UTC [ DST ]


Who is online

Users browsing this forum: Mbohuntr, Norm Johnson and 19 guests



Search for:
Jump to:  


































-->


Privacy Policy :: Powered by phpBB