[Heathkit] [Heath] 6146B Issues

[Glen Zook]

I never said that the 6146B/8298A cannot be made to work in all rigs.  What I do say is that those tubes are problematic in many transmitters and, as such, using them is not always "plug and play"!

I also said that there are those who have had absolutely no problems using the 6146B/8298A in transmitters designed for the 6146 and 6146A/8298.  However, there are plenty of examples where using the later tubes have caused problems.  

I also agree that the "numbers" on the 6146B/8298A are basically the same as the earlier versions.  However, the 6146B/8298A tubes are harder to neutralize in many situations.  Why that?  I have no idea!

I have, somewhere in my files, a letter from RCA acknowledging the fact that the later tubes are not suitable for use in commercial FM two-way transmitters that were designed for the earlier tubes because of the neutralization.
 
Glen, K9STH


Website:  http://k9sth.com



On Monday, October 14, 2013 10:50 AM, L L bahr <pulsarxp at embarqmail.com> wrote:
 
You know, Pete, I have been saying this for years.  However, as soon as you state there is no problem, here comes the famous 6146 again .  The problems stated in this paper have to do with Motorola VHF/UHF equipment and the fact Collins changed their inadequate neutralization capacitor which really had nothing to do with changing over to 6146B tubes.  If you look at the published RCA spec sheet, you will see the differences between both type tubes is extremely minimal.  (I think maybe RCA knows what they are talking about since they invented both the 6146A and 6146B type tubes and also state they are interchangeable.  Then you hear RCA retracted this statement.  However if you ask the person who says they retracted the statement for a copy of the RCA retraction, NONE IS EVER PRODUCED!)  There is no way a ham HF rig will have a problem stemming from moving over to 6146B tubes. If they have a problem, it is because of some other rig problem in the
 rig and not caused by using 61
46B tubes.  So let the lemmings believe their myth.  Both you and I know the truth about this subject.

Lee, w0vt

----- 

I've never run across any of the rigs that I've owned over the last 50
years where 6146B's would not work in place of 6146's and A's and that
includes Heathkit (my original Apache has been running 6146B's since the
70's), Hallicrafters, B&W, Johnson, Kenwood, and others. I won't refute
Glen's original findings (obviously he had a problem with them back then)
but for anyone to say they won't work in all rigs as a replacement is
highly exaggerated. 

Pete, wa2cwa

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