[AMPS] ] SB221 Switches

[km1h@juno.com]

On Mon, 10 Mar 1997 11:45:52 -0500 "Tom Rauch (W8JI)"
<W8JItom@worldnet.att.net> writes:

>The wafers used in all the Ameritron switches interchange with the
>Heathkits but have higher voltage breakdown.

I believe that we better compare apples against apples here before people
start getting real confused. 

The SB220 switch is equivalent to the old Centralab 2500 series of RF
switches. Same source but  custom contact arrangement. It had a 30 degree
index and was prone to burn-out. I dont want to go into the reasons just
yet. A clone switch company in those days was Oak which was also  a Heath
supplier. 
Both bolt up to the Heath index and that exact SB220 configuration is
available in some old 5xx series Tektronics scopes. Those scopes and
plug-ins are dumpster trash at fleamarkets.  

The Ameritron uses the same  basic switch in many of their  amps....the
only difference is the 60 degree  indexing which sure improves the
potential for arc-over. Other than that there is no difference. Same
sources...period.


High quality amps such as ALL Alphas, the Amp Supply LK 800, and others
opted for the Centralab JV series of switches. Other manufacturers went a
step further and incorporated premium Radio Switch Corp switches. A 
properly rated switch will not be the weak link. 

Next point....Centralab has sold all (about 3 yrs ago) of their ceramic
switch division to Electroswitch down in North Carolina. You can guess
what happened to prices!

Final line...I am the owner of Radiokit; a supplier of QRO components.
Tom, W8JI, is the chief "consulting engineer" to MFJ, Vectronics and
Ameritron which are all 100% owned and controlled by MFJ. 
My involvement in QRO is open and evident....I dont hide it. I wish Tom
was as open since his recent discourse to this group was superb.  I
prefer playing on  a level field. 

73....Carl    KM1H   1.8MHz to 10GHz   ex-National Radio 1963-69. 
---

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