[R-390] IF sweep alignment

[KA9EGW]

Trying to do IF sweep alignment so I can look at the bandpass visually.  I
haven't done this since '79, and then the receiver under test was an
HQ-1w29X, with a then-30-year-old 500kc heathkit scope and a 1950's Eico
sweep generator.  Now I'm trying to do it with a HP8640B sig/gen and a 20MHz
dual-trace Hitachi.

So I feed the FM-modulated RF into the antenna input of the 390A, feed the
scope's vertical plates from the IF output on the rear of the 390, and feed
the scope's horizontal plates from the 400Hz sinewave output of the 8640B.
Can't get her to sync up with the scope in x-y mode.

Before I consume too much more bandwidth, is the fact I'm feeding the
horizontal plates with the 400cps modulating freq the problem?  Seems to me
last time I did this that old Heath scope had a sawtooth output on the back
with which I fed the external sweep input on the sweep gen, which sawtooth
output the Hitachi scope doesn't have. :-(

I'm thinking I ought to see if I can borrow a function generator from work
that does sawtooth and feed both the external modulation input of the
generator and the scope's horizontal plates with that.

[Of course I'm also thinking this would be a good excuse to buy a better
scope, but alas, having just acquired that 8640B I dunno if I could get a
new scope past the "Appropriations Committee" HI HI].

Am I on the right track here?  I mean as far as my test setup goes.

73, Brian KA9EGW

-----Original Message-----
From: r-390-bounces at mailman.qth.net [mailto:r-390-bounces at mailman.qth.net]
On Behalf Of Curt Nixon
Sent: Saturday, February 26, 2011 10:26 AM
To: r-390 at mailman.qth.net
Subject: [R-390] My New R-390A Rework Project Blog

GM:

For any interested, here is a link to my blog on re-working my first R-390A
Please feel free to comment there or here--I'm a newbie w/the R-390A so
having a ball scoping out all the istory and information available on-line.

http://curtsworkshop.blogspot.com/

Curt
KU8l
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