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

Go Back   UK Vintage Radio Repair and Restoration Discussion Forum > General Vintage Technology > Components and Circuits

Notices

Components and Circuits For discussions about component types, alternatives and availability, circuit configurations and modifications etc. Discussions here should be of a general nature and not about specific sets.

Closed Thread
 
Thread Tools
Old 22nd Oct 2014, 9:22 am   #1
mole42uk
Nonode
 
mole42uk's Avatar
 
Join Date: Aug 2010
Location: Resolfen, Wales; and Bristol, England
Posts: 2,588
Default Plug-in crystal can sizes?

Hi,
I'm trying to find a source for the older style of plug-in crystal can sizes, in other words I'm trying to find out what I need to specify to replace a 5.35MHz plug-in crystal with a 6.25MHz plug-in crystal.

Any help would be most appreciated.
__________________
Richard

Index:
recursive loop: see recursive loop
mole42uk is offline  
Old 22nd Oct 2014, 9:45 am   #2
G6Tanuki
Dekatron
 
G6Tanuki's Avatar
 
Join Date: Apr 2012
Location: Wiltshire, UK.
Posts: 13,953
Default Re: Plug-in crystal can sizes?

Got any photographs?

The older ones were usually known as "10X" style; then came FT241 and FT243 which were US Government standards.

After WWII two new standards emerged - HC6/U and HC18/U (these last two being typically found in radiotelephone gear from the 1950s through to the 1980s).
G6Tanuki is offline  
Old 22nd Oct 2014, 10:00 am   #3
mole42uk
Nonode
 
mole42uk's Avatar
 
Join Date: Aug 2010
Location: Resolfen, Wales; and Bristol, England
Posts: 2,588
Default Re: Plug-in crystal can sizes?

Unfortunately I'm 200 miles away from the Heathkit IG-37 that uses them so no photos....

I think the one I need to replace is HC6/U - from the pin spacing specification at http://www.af4k.com/crystal_holders.htm I think that's the one. There's also another in the same footprint that is very much taller and a 19kHz crystal.
__________________
Richard

Index:
recursive loop: see recursive loop
mole42uk is offline  
Old 22nd Oct 2014, 10:10 am   #4
Radio Wrangler
Moderator
 
Radio Wrangler's Avatar
 
Join Date: Mar 2012
Location: Fife, Scotland, UK.
Posts: 22,800
Default Re: Plug-in crystal can sizes?

We need a photo to identify the case... with a ruler to show scale because some look the same if you don't have a reference.

We need to know what it's for. Some circuits run the crystal on its series mode, others on its parallel mode. All crystals have both modes but they are different in frequency.

Series mode circuits sometimes add a loading capacitor in series with the crystal, so the frequency can be adjusted a little in either direction. This is allowed for in the design of crystals made for those circuits.

I have several thousand crystals kicking about the place. 5.35MHz, series mode, 30pF load I know I have, but nothing near 6.25MHz.

David
__________________
Can't afford the volcanic island yet, but the plans for my monorail and the goons' uniforms are done
Radio Wrangler is online now  
Old 22nd Oct 2014, 10:10 am   #5
Radio Wrangler
Moderator
 
Radio Wrangler's Avatar
 
Join Date: Mar 2012
Location: Fife, Scotland, UK.
Posts: 22,800
Default Re: Plug-in crystal can sizes?

I must type more quickly....

David
__________________
Can't afford the volcanic island yet, but the plans for my monorail and the goons' uniforms are done
Radio Wrangler is online now  
Old 22nd Oct 2014, 10:23 am   #6
Radio Wrangler
Moderator
 
Radio Wrangler's Avatar
 
Join Date: Mar 2012
Location: Fife, Scotland, UK.
Posts: 22,800
Default Re: Plug-in crystal can sizes?

I've found the heathkit manual.

It's a Pierce oscillator and those use series mode, but it's been simplified quite a lot and it won't oscillate at quite the frequency stamped on the can (some phase shift networks are missing) but for an IF marker, it'll be OK

The existing design uses 5.35MHz, so its 2nd harmonic will mark 10.7 MHz...

So you want 6.25MHz... for a 12.5MHz IF? I'm trying to think what troughlines use...

David
__________________
Can't afford the volcanic island yet, but the plans for my monorail and the goons' uniforms are done
Radio Wrangler is online now  
Closed Thread

Thread Tools



All times are GMT +1. The time now is 11:34 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 - 2024, vBulletin Solutions, Inc.
Copyright ©2002 - 2023, Paul Stenning.