ANTIQUE-RADIO-LAB
Welcome, please log-in to participate in this (your) forum, by logging in you agree to abide by the rules of this forum. Until you make your FIRST post you cannot PM a Member.
ANTIQUE-RADIO-LAB

Antique Radio Forum for Collectors antique-radio-lab.forumotion.com
 
HomeHome  RegisterRegister  Log inLog in  FAQFAQ  PublicationsPublications  SearchSearch  
Need Help Logging In?: 1st. thing is to clean out your cookies. if that doesn't work then Down at the bottom of the page, there is a Contact field that you can click on.
Any other usage, ( other than registration or Login Help) will be ignored. For other questions go to our FAQs link above.

Share | 
 

 Zenith H500

Go down 
AuthorMessage
tubenut
New Member


Join date : 2016-08-03

PostSubject: Zenith H500   August 3rd 2016, 5:28 am

cheers
Has anyone run into this problem?  I have been repairing these radios for many years and this is a strange one.  With the 1L6 installed the audio is a distorted under water sound, however with a 1R5 sub it plays crystal clear.  Any tips would be greatly appreciated.

Tubenut
Back to top Go down
Cliff Jones
Site Administrator
Site Administrator
avatar

Join date : 2010-11-22

PostSubject: Re: Zenith H500   August 3rd 2016, 12:01 pm

I have not heard of that issue before, but one of two things seem appertaining to that. Either the 1L6 tube is getting weak, or a resistor in the grid circuit has changed values, and that is because of age. The 1R5 doesn't have the needed bandwidth for higher frequency stations but works fine on the lower bands.

So if you have a tube tester please check the original 1L6 first, if it checks Ok then you need to check the resistors and capacitors in the Detector/ Oscillator section. Using the other tube will cut off at high frequencies because the tube elements are not as close togather, causing lower performance at high frequencies. 
 You may also check the bias voltage on the grid, but I don't remember what the value of it is,if you do want to measure it be sure to use a digital or VTVM. so as not to load down the bias voltage while measuring.

Hope this helps.
Here is a military manual that is very similar if not exact. See my link below.

http://www.nj7p.org/Manuals/PDFs/Military/R-520%2026-Jan-53%20KG7BZ.pdf

_________________
I'm a Science Thinker, Radio Tinkerer, and all around good guy. Just ask Me!
Back to top Go down
GBClark
New Member


Join date : 2015-07-14

PostSubject: Re: Zenith H500   September 12th 2016, 2:23 am

I wanted to send the tube pin voltage chart from my H500 Service and Restoration Manual as an attachment, but there seems to be no way to do it. Contact me directly at gc@sdlcforms.com if you want it and I will e-mail it to you.

Gary Clark
Back to top Go down
Sponsored content




PostSubject: Re: Zenith H500   

Back to top Go down
 
Zenith H500
Back to top 
Page 1 of 1
 Similar topics
-
» ZENITH 2016 - Part Eight
» Romney Says May Fulfill White Horse Prophecy In Zenith 2016
» Did Something Begin In 2012... That Will Zenith In 2016?....THE FOURTH TURNING
» Muslim Website Says Mahdi (Antichrist?) Will Be Here In Zenith 2016, And Jesus Will Follow Afterward

Permissions in this forum:You cannot reply to topics in this forum
ANTIQUE-RADIO-LAB :: Radio Repair Bench :: Radios -Tube type-
Jump to: