I have a line on an old Hammarlund HX-50 transmitter in unknown condition
(been sitting on the shelf for years).

It would be a nice match to my HQ-180A.

General consensus with old radios like that, particularly transmitters, is
that the first thing one should do is replace the old electrolytic and
paper capacitors.

My question is, what's the worst that's likely to happen if one doesn't do
that? Bring it up on a variac, a capacitor blows, makes magic smoke
happen, XYL gets really upset :-), and the fuse blows.

Some have said you can blow the power transformer but wouldn't the fuse
blow first (unless the power transformer was ready to go anyway)?

General question... which is the best website for information on restoring
old radios? (I know I can google on "restoring old radios" but I'm
looking for opinions on the best from among the few hundred thousand hits
that are likely to come up.)

Thanks...

Rick (W-A-one-R-K-T) wrote:
I have a line on an old Hammarlund HX-50 transmitter in unknown condition
(been sitting on the shelf for years).

It would be a nice match to my HQ-180A.

General consensus with old radios like that, particularly transmitters, is
that the first thing one should do is replace the old electrolytic and
paper capacitors.

My question is, what's the worst that's likely to happen if one doesn't do
that? Bring it up on a variac, a capacitor blows, makes magic smoke
happen, XYL gets really upset :-), and the fuse blows.

Some have said you can blow the power transformer but wouldn't the fuse
blow first (unless the power transformer was ready to go anyway)?

General question... which is the best website for information on restoring
old radios? (I know I can google on "restoring old radios" but I'm
looking for opinions on the best from among the few hundred thousand hits
that are likely to come up.)

Thanks...


Rick, Looks like you've already stated the standard routine of
restoration, or at least the commencement, thereof. The HX-50 is not
super old so you may not have too much in the way of out-of-tolerance
resistors, for example. It doesn't take a lot to check an electrolytic
before actually bringing it up, assuming you've accumulated a
(e.g.Heath cap checker. Normally, bringing something up on the Variac
does give a bit of safety for the equipment, but not guaranteed. You
can still be in some degree of overload and damage may still occur. You
might consider putting a smaller than called for fuse in the rig and
bring it up, initially, that way. With no appreciable p.s. load, and
the additional protection, you may be able to safely test and/or reform
the electrolytics. Just a thought........
de K3HVG

"Rick (W-A-one-R-K-T)" wrote in message
news

I have a line on an old Hammarlund HX-50 transmitter in unknown condition
(been sitting on the shelf for years).

It would be a nice match to my HQ-180A.

General consensus with old radios like that, particularly transmitters, is
that the first thing one should do is replace the old electrolytic and
paper capacitors.

Replacing paper caps, electrolytics, and out of spec' or stressed resistors
is part of doing a restoration.


My question is, what's the worst that's likely to happen if one doesn't do
that? Bring it up on a variac, a capacitor blows, makes magic smoke
happen, XYL gets really upset :-), and the fuse blows.

It sounds like you want to hear you should take the easy way out.

Some have said you can blow the power transformer but wouldn't the fuse
blow first (unless the power transformer was ready to go anyway)?

Are you a gambler? You're bias supply could fail and take out the final
tubes;
the transformer could fail; cleaning the mess after the electrolytics
explode is always fun.

And, you can't reform the caps using a variac... There's no cathode emission
from the rectifiers until the AC supply is above a certain voltage.


General question... which is the best website for information on restoring
old radios? (I know I can google on "restoring old radios" but I'm
looking for opinions on the best from among the few hundred thousand hits
that are likely to come up.)

Thanks...


Try Phil Nelson' site:

www.antiqueradio.org

On Sat, 22 Sep 2007 11:17:43 -0400, Uncle Peter wrote:

It sounds like you want to hear you should take the easy way out.

Good afternoon, Uncle Peter.

I have been on the Internet since before most people knew the Internet
existed, and I have always wondered what it is about Usenet (and Fidonet
and RIME and all those BBS networks that came before the Internet) that
makes people feel compelled to put other people down for no good reason.

If we were sitting around the shack here, talking about this stuff over
pizza and some cans of beer, would you talk to me like that? Maybe so ...
but really I suspect not, you don't strike me as that type.

I would think by now that regulars on this NG would know that I'm new to
this stuff and am just looking to learn.

There's "taking the easy way out" and there's "not fixing what ain't broke".

I'm currently working on a DX-40 restoration and I have been advised to
strip out all of the components and wiring and rebuild it from scratch
with all new components (where available).

Seems like a bit of overkill to me.

Saving the bias supply, and protecting other components from shrapnel when
a capacitor blows, all seem like good reasons to replace the caps. So, I
learned something today, just like I do just about every time I post
something here (thanks).

(On the other hand, bias supplies fail for reasons other than blown caps...)

I'll try Phil Nelson's site ... thanks...

"Rick (W-A-one-R-K-T)" wrote in message
news
On Sat, 22 Sep 2007 11:17:43 -0400, Uncle Peter wrote:

It sounds like you want to hear you should take the easy way out.

Good afternoon, Uncle Peter.

I have been on the Internet since before most people knew the Internet
existed, and I have always wondered what it is about Usenet (and Fidonet
and RIME and all those BBS networks that came before the Internet) that
makes people feel compelled to put other people down for no good reason.

If we were sitting around the shack here, talking about this stuff over
pizza and some cans of beer, would you talk to me like that? Maybe so ...
but really I suspect not, you don't strike me as that type.

I would think by now that regulars on this NG would know that I'm new to
this stuff and am just looking to learn.

There's "taking the easy way out" and there's "not fixing what ain't
broke".



What can I say. You asked for advice, and still doubt the veracity of the
advice. "Fixing what ain't broke" pretty much conveys the original
supposition of taking the easy way out.

A proper restoration involves changing parts that WILL fail, and that
includes electrolytics and paper capacitors. If you just want to get
it running, then you take your chances.

If you've been around that long, then certainly know what to
do without asking for blessings. And yes, this is usenet.

73

Pete

"Rick (W-A-one-R-K-T)" wrote in message
news
On Sat, 22 Sep 2007 11:17:43 -0400, Uncle Peter wrote:

It sounds like you want to hear you should take the easy way out.

Good afternoon, Uncle Peter.

I I'm currently working on a DX-40 restoration and I have been advised
to
strip out all of the components and wiring and rebuild it from scratch
with all new components (where available).


Seems like I was one of the first that responded on thread as well. I don't
remember advising you to strip all of the components and to rebuild it
from scratch.. But, on the other hand, if someone was doing a full
restoration that certainly wouldn't be unheard of. Most of the advice
you received was pretty much on the mark. Again, if you ask
for advice on usenet, I suggest you either develop a thicker skin or
keep a more open mind.

73

Pete

Rick (W-A-one-R-K-T) wrote:
On Sat, 22 Sep 2007 11:17:43 -0400, Uncle Peter wrote:

It sounds like you want to hear you should take the easy way out.

Good afternoon, Uncle Peter.

I have been on the Internet since before most people knew the Internet
existed, and I have always wondered what it is about Usenet (and Fidonet
and RIME and all those BBS networks that came before the Internet) that
makes people feel compelled to put other people down for no good reason.

Hi Rick,

Communication is a two way street. What appears harsh to a reader might
have seemed harmless to the sender. I have been told that I write mean.
That surprises me, because I am a nice and gentle person. I suspect that
what bothers some people is I work hard to make sure that my posts are as
grammatically and factually correct as I can. That means that I have lots
of details in my posts, and lots of things that might appear as being
condescending.

When you read some one's post or reply, imagine that they aren't trying
to put you down. 99% of the time you will be correct. Imagine that writing
might be a bit challenging. That will also get you another 99%, if school
scores are any indication. Keep your skin thick. That way when someone does
try and make you feel bad, you will be as immune as possible to their bullying.

Uncle Peter is a good guy. I don't think he meant to be rough with you.

-Chuck

On Sat, 22 Sep 2007 20:11:38 -0400, Chuck Harris wrote:

When you read some one's post or reply, imagine that they aren't trying
to put you down. 99% of the time you will be correct. Imagine that
writing might be a bit challenging. That will also get you another 99%,
if school scores are any indication. Keep your skin thick. That way
when someone does try and make you feel bad, you will be as immune as
possible to their bullying.

Uncle Peter is a good guy. I don't think he meant to be rough with you.

Good evening, Chuck.

Yeah, I know... he seems that way most of the time, which is why I kind of
wondered why he felt the need to say what he said. Believe me my skin is
plenty thick :-) ... usually I just ignore things like that, knowing
that's the way things are around here. Every once in a while, though,
something hits me just so and I have to ask myself why in the world so
many people seem to find the need to say on Usenet what they would never
say to someone's face.

It's nothing new. I'm an old Fidonet sysop from the 1980's and people did
the same things back then. Never quite understood it then and don't
really fully understand it now, but yes, it's the way things are, and just
about all the time I just suck it up and move on.

As Pete said in another message, "yes, this is usenet"... as though that
explained everything. Maybe it does.

No big deal. :-)

Thanks...

Rick (W-A-one-R-K-T) wrote:

I have a line on an old Hammarlund HX-50 transmitter in unknown condition
(been sitting on the shelf for years).

It would be a nice match to my HQ-180A.

General consensus with old radios like that, particularly transmitters, is
that the first thing one should do is replace the old electrolytic and
paper capacitors.

My question is, what's the worst that's likely to happen if one doesn't do
that? Bring it up on a variac, a capacitor blows, makes magic smoke
happen, XYL gets really upset :-), and the fuse blows.

Depends on the radio.

In the case of receivers, interstage coupling caps that are paper can fail
into a short, and take out an IF can. You can't get replacement IF cans
easily these days. So this is a catastrophic failure.

Transmitters are less apt to have delicate things like this to fail, but
they also have less delicate things that are more dramatic when they do
fail.

Some have said you can blow the power transformer but wouldn't the fuse
blow first (unless the power transformer was ready to go anyway)?

Sadly, not. Especially if you run the rig for a long time with the
transformer overheating but the total current below the fuse current.
Remember, the fuse is sized to allow a large starting current in most
cases.

Using an inrush current limiter allows you to use a smaller fuse, which
protects you from such things. I recommend this in newer designs but of
course it's not in place in most boatanchors unless you retrofit it.

Also realize that when can caps fail, the resulting shrapnel can sometimes
damage plenty of other stuff.

General question... which is the best website for information on restoring
old radios? (I know I can google on "restoring old radios" but I'm
looking for opinions on the best from among the few hundred thousand hits
that are likely to come up.)

I don't know.
--scott
--
"C'est un Nagra. C'est suisse, et tres, tres precis."

"Scott Dorsey" wrote in message
...
Rick (W-A-one-R-K-T) wrote:
Using an inrush current limiter allows you to use a smaller fuse, which
protects you from such things. I recommend this in newer designs but of
course it's not in place in most boatanchors unless you retrofit it.
I don't know.
--scott
--
"C'est un Nagra. C'est suisse, et tres, tres precis."

Excellent advice; and the ICL get's rid of the transformer "THUMP"
when the rig is switched on at the crest of a cycle.
It also does a lot to enhance the remaining
power switch contact point life.

Pete