[Boatanchors] Spectrum analyzer?

[manualman at juno.com]

Responding to your two posts:

Obviously, if you really read either manual (specifications in the
Owner's manual page 3 or service manual page 18), you would probably
understand more clearly.

As designed and supplied, the BS-8 was designed to work with the TS-820
and TS-830 series IF frequency of 8830 KHz. Further, the BS-5 was
designed to work with the TS-520S series IF frequency of 3395 KHz. Both
BS-5 and BS-8 are identical except for the input IF frequency. Neither is
wired from the factory to provide a 455 KHz input to connect to the
existing jack on the back of the SM-220. Obviously, in your case (BS-8),
if you disable the 8830 KHz oscillator and input IF transformer (T201),
and wire the IF input of the BS-8 to the input of the 455 KHz ceramic
filter, then the BS-8 or the BS-5 for that matter will work with a 455
KHz IF. The bottom line is that neither BS-5 or BS-8 with a SM-220
provide any real accurate spectrum analysis. It allows you to see signals
on either side of your center frequency, but, at best, it's really
nothing more then an eye candy visual display without a lot of substance.

Since it lacks any high degree of accuracy when used with receivers I
wouldn't recommend it. As an RF monitor and a decent CRT (still bright
and no burn spots), it can provide some use but with the availability of
the CRT at zero, and no direct substitutes, I would not recommend any one
going out to find and buy one. Fortunately my SM-220, with the BS-8 which
I bought in 1982, still has a decent trace on it but I only use it for RF
monitoring of my transmissions.

Pete, wa2cwa


On Thu, 15 Dec 2011 17:48:42 -0500 rbethman <rbethman at comcast.net>
writes:
> Sorry Pete.
> 
> Mine specifically states 455Kc.
> 
> I use the IF out of the R-390A or the SP-600 to use the BS-8.
> 
> You may want the owners manual and service manual.
> 
> Bob - N0DGN

****Then, in a later e-mail you said:

I stated read the Service Manual.
 
Why?
 
The down converter can be bypassed and then feed directly with 455Kc to 
the 455Kc filter.
 
I've been running it that way for years.
 
I can repair my own equipment too.
 
How else to keep R-390As and an SP-600 running along with a BC-610 and a 
T-213?
 
Bob - N0DGN