Call Search
     

New to Ham Radio?
My Profile

Community
Articles
Forums
News
Reviews
Friends Remembered
Strays
Survey Question

Operating
Contesting
DX Cluster Spots
Propagation

Resources
Calendar
Classifieds
Ham Exams
Ham Links
List Archives
News Articles
Product Reviews
QSL Managers

Site Info
eHam Help (FAQ)
Support the site
The eHam Team
Advertising Info
Vision Statement
About eHam.net

   Home   Help Search  
Pages: [1]   Go Down
  Print  
Author Topic: Hallicrafters Transmitter Model HT-40  (Read 962 times)
KA5PNE
Member

Posts: 1




Ignore
« on: May 16, 2002, 05:20:36 PM »

What could be the single most or even combination of problem(s) that causes a vintage transmitter like this to produce "...a filtered tone, definite trace of ripple modulation..."?  Tube, Caps(s), both?  Have you experienced this problem before?  Your feedback will be gratefully appreciated.
Logged
KD7KOY
Member

Posts: 97




Ignore
« Reply #1 on: May 18, 2002, 12:16:22 AM »

Some may disagree, but a rig that old, I would change the caps before even trying it on the air.
All my tube rigs have been recapped, if nothing else than for peace of mind and I have eliminated a potential problem. This includes filter caps.
Caps get leaky with age and some can short.
Check the resistors also while your in there. Anything out out of tolerance, change it.
You can get caps at AES.
The tubes can be checked but some tube testors only check for shorts etc.
It's not an "overnight" project, but you will learn alot about your rig in the process and in the end have a set that works as new.
I personally find it fun.
If you don't have the manual, get it. it's a "must have" item for any restoration.
Just a word of caution. High voltage is present, Dangerous. If you have not worked around the tube gear, find someone who has before you tear it apart.
Disconnect the unit and discharge any caps before working on it.
Good luck.
Logged
W9GB
Member

Posts: 2659




Ignore
« Reply #2 on: May 19, 2002, 10:26:40 AM »

The HT-40 was my Novice trasnmitter in the earlier 1970's

I would agree with the comment of replacing the paper and electrolytic capacitors (Orange Drops work well for the paper replacements) .. heat probably has dried out the elctrolytics

The other issue you have to watch for on this model is the mode switch on lower left corner.  Look for arcing or dirty contacts (that problem confounded me for a few days)

w9gb
Logged
Pages: [1]   Go Up
  Print  
 
Jump to:  

Powered by MySQL Powered by PHP Powered by SMF 1.1.11 | SMF © 2006-2009, Simple Machines LLC Valid XHTML 1.0! Valid CSS!