"West" wrote in news:OQ53j.37950$Xg.23109@trnddc06:


"James Sweet" wrote in message
news:no13j.19418$XT.16175@trnddc01...

wrote in message

...
Greetings,

I have a ('77 ?) Tektronix 485 scope (serial starts with a 'B' or
an '8', number is 167020) that I received 4 years ago. At the time
it worked, although I was (still am somewhat) pretty "green"
regarding electronics as I am more of a hobbyist than a
professional as I love to learn and "tinker". In the past, I have
serviced tube amplifiers for friends. Right now I have a 3M
(Mincom) M56 professional multitrack tape recorder I am currently
in the process of aligning. I guess you could say I am an "analog
dinosaur" of sorts... LOL.

When I initially got the 485, the unit powered up and I could do
some basic sweeps, but I have not really used it since I initially
got it (mainly due to getting married, having kids and buying a new
house - funny how those things take up gobs of your life ;-). When
I went to turn it on about a year ago, I noticed a clicking or
chirping with no beam. Apparently as I understand it based on some
quick research on the 'net, this is not an uncommon symptom on
these 'scopes having a power supply trying to start but failing due
to current overload of some sort (capacitors?).

So, I did a search on Tektronix repair and came up with a person
that thinks they will be able to fix it.

However, for the price of the repair (and maybe a little more), I
am wondering if I wouldn't be better served with something like a
2465/A/ B?

Here's some reasons why maybe I think I should go with the 2465:

1) Compared to the 485, it's a newer 'scope with perhaps less hours
than my 485 (don't know how much use my 485 has had; it appears to
be in average or slightly better condition)
2) Less "mechanical" parts in the 2465 (e.g., pots, etc. from my
understanding) to fail
3) Lots think this is the epitome of the analog oscilloscope

Reasons why I should maybe stay with my 485:

1) Better proprietary IC availability (?, don't beat me up; I
thought this was what I read...)
2) Easier to service/repair than the 2465
3) More robust for the beginner

Obviously if I am thinking like this, I have no idea what I should
ultimately do. What does everyone think? ducking


The 485 is a really excellent scope, and the problem you describe
should
be
fairly easy to repair. There's no sense in upgrading, as a beginner
you probably won't use a large portion of the features the 485
provides even.

Hi James. I had a 485 many years ago to use for field work ( not that
easy schlepping it around the country). I think it had a 250 MHz
bandwidth. It's really packed so be careful when attempting repairs.
Starting with checking the low voltage power supplies is a good idea.
Also be careful if sending it out prepaid for service. Check the
service place thoroughly for references and for viable guarantees. The
485 is a professional scope that way exceeds the hobbyists
requirements. So if you can repair it reasonably, you will own a
classic gem.

Cordially,
west





if you ship it anywhere,**pack it very well**,with at least 3-4 inches of
padding on EVERY side,top,and bottom.

Using loose peanuts is a great way to have your scope smashed up.
Better to pack the peanuts in plastic bags,making "pillows" and place those
around the scope.

I've seen plenty of poorly packed instruments,and UPS/FedEx/DHL/USPS is not
liable for poorly packed items.

--
Jim Yanik
jyanik
at
kua.net