Reply
 
LinkBack Thread Tools Search this Thread Display Modes
  #1   Report Post  
Old September 6th 03, 02:29 PM
John
 
Posts: n/a
Default Hallicrafters SX-76 Help

1. Does the fact that this set has double conversion make it more
sensitive or selective ? It seems to be no better than my S-40B ?
2.The volume and sensitivity controls must be at almost set to
maximum to receive anything on 80 meters or higher. Is this normal ?
Any suggestions on what to check ?
3.Will this set be more sensitive on a di-pole antenna ?
I only have a vertical connected to the co-ax connection .
4.The selectivity controls has two capacitors about 1.25" long and3/8"
thick with red, red, orange, white, blue bands. What is value ?

I have replaced all caps, bad resisters and none of the tubes have
shorts. The alignments seems fairly decent on all bands, but I have
not attempted to adjust. (Don't trust myself to do this...).

Any and all help is appreciated.

Thanks,
John

  #2   Report Post  
Old August 16th 08, 09:52 AM posted to rec.radio.amateur.boatanchors
external usenet poster
 
First recorded activity by RadioBanter: Aug 2008
Posts: 12
Default Hallicrafters SX-76 Help

On Sat, 06 Sep 2003 13:29:08 +0000, John wrote:

1. Does the fact that this set has double conversion make it more
sensitive or selective ? It seems to be no better than my S-40B ? 2.The
volume and sensitivity controls must be at almost set to maximum to
receive anything on 80 meters or higher. Is this normal ? Any
suggestions on what to check ?
3.Will this set be more sensitive on a di-pole antenna ? I only have a
vertical connected to the co-ax connection . 4.The selectivity controls
has two capacitors about 1.25" long and3/8" thick with red, red, orange,
white, blue bands. What is value ?

I have replaced all caps, bad resisters and none of the tubes have
shorts. The alignments seems fairly decent on all bands, but I have not
attempted to adjust. (Don't trust myself to do this...).

Any and all help is appreciated.

Thanks,
John


The double conversion reduces image response compared to
the the S-40. This becomes a problem above 10-20 MHz
depending on the Q of the RF coils and how well the radio
is aligned.

The 5 selectivity choices on the S-76 would help receive
weak signals.

The S-40 is a much simpler radio and easier to align.
The S-7 alignment procedure calls for a 50 KHz signal
which is not provided by most signal generators.

The large S-meter on the S-76 provides a multimedia
experience which has no counterpart in the S40.
--
Chuck Forsberg www.omen.com 503-614-0430
Developer of Industrial ZMODEM(Tm) for Embedded Applications
Omen Technology Inc "The High Reliability Software"
10255 NW Old Cornelius Pass Portland OR 97231 FAX 629-0665
  #3   Report Post  
Old August 16th 08, 05:21 PM posted to rec.radio.amateur.boatanchors
external usenet poster
 
First recorded activity by RadioBanter: Mar 2008
Posts: 618
Default Hallicrafters SX-76 Help

On Sat, 16 Aug 2008, Chuck Forsberg WA7KGX N2469R wrote:

On Sat, 06 Sep 2003 13:29:08 +0000, John wrote:

1. Does the fact that this set has double conversion make it more
sensitive or selective ? It seems to be no better than my S-40B ? 2.The
volume and sensitivity controls must be at almost set to maximum to
receive anything on 80 meters or higher. Is this normal ? Any
suggestions on what to check ?
3.Will this set be more sensitive on a di-pole antenna ? I only have a
vertical connected to the co-ax connection . 4.The selectivity controls
has two capacitors about 1.25" long and3/8" thick with red, red, orange,
white, blue bands. What is value ?

I have replaced all caps, bad resisters and none of the tubes have
shorts. The alignments seems fairly decent on all bands, but I have not
attempted to adjust. (Don't trust myself to do this...).

Any and all help is appreciated.

Thanks,
John


The double conversion reduces image response compared to
the the S-40. This becomes a problem above 10-20 MHz
depending on the Q of the RF coils and how well the radio
is aligned.

The 5 selectivity choices on the S-76 would help receive
weak signals.

The S-40 is a much simpler radio and easier to align.
The S-7 alignment procedure calls for a 50 KHz signal
which is not provided by most signal generators.


If it's a 50KHz final IF, then that would tend to give better
selectivity. After all, at that frequency you can get plenty of
narrow bandwidth without anything more than a few IF transformers.

It's not just the selectivity, but you get better shape factor
with just the IF transformers at 50KHz as opposed to 455KHz.

And they wouldn't go to the trouble of dropping to 50KHz unless
they were seeking better selectivity than 455KHz would offer.

And given a 50KHz IF, they didn't have much choice but to go
to double conversion, since a 50KHz IF would mean either lousy
image rejection or a lot of tuned circuits at the signal frequency.

Michael VE2BVW
Reply
Thread Tools Search this Thread
Search this Thread:

Advanced Search
Display Modes

Posting Rules

Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are On
Pingbacks are On
Refbacks are On


Similar Threads
Thread Thread Starter Forum Replies Last Post
SOLD: Hallicrafters SX-43 WZ1U Boatanchors 0 August 23rd 03 12:41 AM
FS: Hallicrafters SX-43 ($30) WZ1U Boatanchors 0 August 23rd 03 12:24 AM
FS/FS Hallicrafters SR150 Monte Boatanchors 0 August 20th 03 01:11 PM
FS: National, Millen, and Hallicrafters and Vibroplex Stuff Dave Hollander Boatanchors 0 August 16th 03 07:38 PM
FS Hallicrafters BC-610-II have a Hallicrafters BC-610I that looks like it has not many hours usage. It has been stored for about 15 years until discovered by me a few days ago. The cabinet is in excellent shape for a 60 year old rig. Three tubes ac5tx Boatanchors 0 July 28th 03 11:30 PM


All times are GMT +1. The time now is 11:36 AM.

Powered by vBulletin® Copyright ©2000 - 2024, Jelsoft Enterprises Ltd.
Copyright ©2004-2024 RadioBanter.
The comments are property of their posters.
 

About Us

"It's about Radio"

 

Copyright © 2017