Astron RM 50 M Repair DONE!

[Jack Crow]

Guys,
I have a club Astron RM 50M on the bench that one of the members gave me to fix some time back.
Since the club was in no rush, neither was I.

Took some photos you might want to look at.
http://www.flickr.com/photos/9010884...th/8397734825/

These are not all that hard to fix. You may want to get into the 'business' as well.

Bruce (the club repeater maven) reported the symptom as the the OVP (Over Voltage Protector) would fire and shut down the supply.
For no known reason.

Anyhow, upon opening it up this AM, it was in rough shape.
It's bent. Somewhere in it's past the unit was dropped.
This sprung a bunch of fasteners.
Loose mechanicals make for poor performance in the real world.

I drilled out the stretched pop rivets and replaced them with self taping screws, then torqued them in.

Then I went to tighten up the electrical connections.
All the transistors took a quarter turn twist or better.
Same for the screw terminals on the filter caps.
In fact the - side connection to the regulator board took more than a little bit to tighten.
Suspect that may have been the cause of the flaky operation.

The circuit board was another freak show.
Looks like it had not been cleaned since it was made.
Old flux takes on a gummy look and tends to get conductive.
Got out the brush and solvent, took the gunk off the board and it looks much better.

Turned the thing on.

The front panel voltage meter showed zero volts output.
Measured with an external meter, and it showed 13.76 volts.
Another casualty of the drop was the meter movements.
The current meter was useless as well.

Hooked it up to the solid state dummy load I use for power supply's.
I can draw 35 amps with the thing, no flaws
Less than 1mV ripple as measured on the HP3456A.
Voltage drop at load is trivial, about 150mV zero to 35 amps.

I banged on it, no trips.
Just fired my 2M HT next to it with the covers off, and it did not trip.

Calling this one done unless the club wants to buy new meters for it.

Jack Crow

[smason]

Re: Astron RM 50 M Repair DONE!

Cool.
For an Astron, it looks a bit sloppy.
I've never been inside a 50, but I don't recall the 35s looking quite so "home made"

[vinceroger69]

Re: Astron RM 50 M Repair DONE!

not many people i know of tend to repair radio equiptment i do see a lot of faulty 80 channel cb radios on ebay and car boots being sold faulty can these be easily fixed with basic equipment usually? i might look into buying a couple also i have the same canon camera as your using what mode settings are you using to take the great quality photos like you do as i am having trouble setting my canon up.

[smason]

Re: Astron RM 50 M Repair DONE!

What amazes me is Hams. We tend to be pretty technical, and passing the exams is *supposed* to prove you have half a clue. But many hams wouldn't know which end of a soldering iron to hold.
A linear power supply is pretty basic and easy to repair.

True story, I once had to go to a Ham's place (A Canadian ADVANCED ticket holder) to solder a 1/4" phone plug on his CW key!
Seriously. 2 wires, polarity not really an issue, you'd have to work hard to do it wrong.
In fact the 1/4" plug had screw terminals so it didn't really even need soldering.

Well at least he was doing CW...

And no I'm not a CW snob. Haven't touched a key since my last exam in '88
I'd be hard pressed to copy anything over 4wpm.

[Jack Crow]

Re: Astron RM 50 M Repair DONE!

Guys,
Truth in what your saying.

Samson,
It was a bit simple.
I'm not the first into it and I doubt I will be the last.
It came out of a club repeater site and the guys were thinking that the OVP tripps from RFI.

I have my own ideas.

For the moment the goal was to get it running and make it stable.
That seems to be the case.

Talked to the client and it will be going back Tuesday.
So until then it's going to be tail weight for my car.

As for hams being useful. Some are, and some are not.
I can pick on them, but that is too easy.
I call it a "No Screw Driver Extra"
Then again, they can do things that I can't, like a tax form.
The dam things beat me up badly.

Vin,
Many years ago I started as a cb mechanic back in the late 70's. US style, 23 then 40 channel AM units. Still get some now and then people want working.

As for the camera settings.
What can I say. I set the zoom to minimum and use the macro setting.
Plus as much light as possible for even a little bit of depth of field.
Patrice never hurts.

If you need detailed settings, I can use my other camera to photo graph the menus on the 1200 if that would help.

Thanks for the responses.
Jack Crow
Herndon VA

[Heihachi_73]

Re: Astron RM 50 M Repair DONE!

I have a Canon PowerShot A2000IS, it's absolute junk if you use it as a point and shoot indoors or in low light. On the other hand, it can take very good pictures if you set it up on a tripod or table and use the self-timer to avoid motion blur. Macro mode is a must for taking pics of PCBs and the like, or else the thing will never focus unless you're a mile away from what you're trying to photograph. Also, let the ambient light in rather than using the flash, or else every single piece of metal on the board will become bright white and cause bad glare.

[vinceroger69]

Re: Astron RM 50 M Repair DONE!

jack only if you get a minute some detailed settings would be great if you dont mind doing them but no rush at all and many thanks heihach_73 those tips are great was looking at the tripods yesterday on ebay so will defently order one now.
i think a lot of my issues is with the lighting yes i took them on the window sill but it was not sunny we dont have that much in the uk lol.(still deep in snow still about -4 as well) so cant even get out to pick up items to test my repair skills on.
jack also before i go and purchase any radio equptment i am going to join the local online cb club to just see how popular it still is in the uk .years ago every other car used to have a mag mount/gutter mount on now you hardly see any other than the hgvs of course.

[Jack Crow]

Re: Astron RM 50 M Repair DONE!

Vin,
Its 0dark30 here and I have to go to the day job.
Will try and get your settings this evening after hours.
Jack Crow

[vinceroger69]

Re: Astron RM 50 M Repair DONE!

no rush at all honest thanks for you help and guidance
vince

[Jack Crow]

Re: Astron RM 50 M Repair DONE!

Vin,
I doubt this is going to help much.

http://www.flickr.com/photos/9010884...7632578031821/

Is this what you were after?

If there is some sub menu specific thing, let me know.

There is no secret to macro photography.
These little point and shoot units are capable of some amazing things if presented to the sensor properly.

Guess three years of photography in High School was good for something.

Hope all is well on your side of the pond.


Mike / Jack Crow

[vinceroger69]

Re: Astron RM 50 M Repair DONE!

thanks mike i have set them as per your settings now one last question on the camera the top right round knob which is the setting you use p live auto scn etc?
And all well here this side of the pond just cold -5 last night still about 6 inches plus snow and ice the trouble is in the uk a light dusting of snow and everything comes to a stand still (last time it was this bad in my area it was in 1985) were just not used to the snow and ice in our part of the uk although it does not stop me going out as long as my fuels not frozen in the car (i have done a vegetable oil conversion on my car so i can use new/ used vegetable oi)l as the prices of fuel over here are stupid in my opinion its about £1.38 petrol liter and £1.40 diesel liter.
cheers agian vince

[vinceroger69]

Re: Astron RM 50 M Repair DONE!

one last question just turned camera on with top round knob on the p setting then pressed func set button what iso setting is yours set to? that has something to do with picture quality? cheers again mike regards vince

[Jack Crow]

Re: Astron RM 50 M Repair DONE!

Vin,
Sorry for the delay. Went to a radio club meeting last night.
Ages ago I used to do a lot of public service stuff ARES/RACES, similar to your Raynet stuff. They use radios I make for covering a major foot race here called the Marine Corps Marathon.

The day job has me in fits.
We had about 6 weeks of very little to do, and now we have a few days of way too much to do.

Your Q

"one last question on the camera the top right round knob which is the setting you use p live auto scn etc? "

It's set to the AUTO position.
Haven't used the others, have not needed to.
Not exactly sure what they are.

Here in Virginia we are enjoying a cold snap as well.
Last week we had temps in the low 50's (F) , spent the day telling people how much I liked global warming.

This morning it was below the freeze point.

My vehicles use no lead gasoline, diesel engines in cars here are rather rare.
MB's, some VW's. Not much else. D cars out of detroit suffered in the mid 80's when Oldsmobile tried to make a V8 Diesel. It was a pile of crap. Cost them a fortune in warranty repairs. Most of those cars were converted to gas. To this day, I know of no US made cars with a D option.

Personally I think they are a great idea. It's the rest of the country that is ass backwards in their thinking.

This thing is my 'daily' driver. An '07 Scion TC.
Think of it as my second mid life crisis.
http://www.flickr.com/photos/9010884...7604647482795/
Check out the tag.
It's one of the few 'offensive' license plates in the state.
If Virginia grabs it back some day, I will ask for LB SIO2, that will take twice as long to figure out. Once in a while someone gets it. For the most part I get the reaction similar to this. Ever talk to a dog? They twist their heads and look confused? That is what most people do when they see the tag. Head twist and don't get it.

Also have a full size pick up truck. Don't have any good photos of that.
2 wheel drive, big V6 (4.2L) coupled to an automatic. It has well over a 'light second' on it. The odometer quit at 225k miles. Speed of light is 186K miles per second. Should be well on it's way to a second light second. Not bad for an 89 model year.

Some time back I had a retired Police Pack Dodge Diplomat.
http://www.flickr.com/photos/9010884...7605006909722/
The tag on that said "Immune" as in Diplomatic Immunity.
Remember I live near the national capitol, so it got some cute giggles from time to time. It got too expensive to fix while I was un employed.

The wife's car is a silver Prius. Great bit of equipment even if the Top Gear guys hate it.

As for the price of fuel, I don't have a mental converter from gallons to liters.
Almost had the knack of it in Kuwait, but that was 'long ago and far away'.

Where the wife and I go it's about 3.45/Gal here. It shifts up and down depending on the markets and if the Mid East has a snit.


Hope that helps.

Mike aka Jack Crow in VA

[vinceroger69]

Re: Astron RM 50 M Repair DONE!

many thanks again mike much appreciated your vehicles are great some good pics will have another look into them when i get more time and thanks i am sure basically where i am going wrong with my pictures is just the lighting situation i think i may try a bit of overhead led lighting or something as its pretty dull here still and more snow forecast next few days. thanks again vince

[kc8adu]

Re: Astron RM 50 M Repair DONE!

someone has lb nacl here.saw it a while back.

Check out the tag.
It's one of the few 'offensive' license plates in the state.
If Virginia grabs it back some day, I will ask for LB SIO2, that will take twice as long to figure out. Once in a while someone gets it. For the most part I get the reaction similar to this. Ever talk to a dog? They twist their heads and look confused? That is what most people do when they see the tag. Head twist and don't get it.

Also have a full size pick up truck. Don't have any good photos of that.
2 wheel drive, big V6 (4.2L) coupled to an automatic. It has well over a 'light second' on it. The odometer quit at 225k miles. Speed of light is 186K miles per second. Should be well on it's way to a second light second. Not bad for an 89 model year.

Some time back I had a retired Police Pack Dodge Diplomat.
http://www.flickr.com/photos/9010884...7605006909722/
The tag on that said "Immune" as in Diplomatic Immunity.
Remember I live near the national capitol, so it got some cute giggles from time to time. It got too expensive to fix while I was un employed.

The wife's car is a silver Prius. Great bit of equipment even if the Top Gear guys hate it.

As for the price of fuel, I don't have a mental converter from gallons to liters.
Almost had the knack of it in Kuwait, but that was 'long ago and far away'.

Where the wife and I go it's about 3.45/Gal here. It shifts up and down depending on the markets and if the Mid East has a snit.


Hope that helps.

Mike aka Jack Crow in VA