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Author Topic: Johnson Viking Ranger 2 Advice Requested  (Read 15750 times)
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WD4DMZ
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« Reply #25 on: February 07, 2018, 07:10:20 PM »

Hmmm. I missed that one. Any pictures? Did you see the one with the crumbling power cord? Aside from the cord it was pretty clean.

Rich
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KG6PQQ
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« Reply #26 on: February 16, 2018, 11:49:53 AM »

The cord is frayed, I’m replacing the cord with a filtered fused socket


* FCD1CCD1-4807-4B7C-BA90-9808A1DD7C65.jpeg (1611.16 KB, 3264x2448 - viewed 416 times.)
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WD4DMZ
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« Reply #27 on: February 16, 2018, 01:21:47 PM »

That is a nice one. I'm surprised I missed seeing it unless you purchased it early in the morning. I did not get there until 11:30.

Looks like a great find.

Rich
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WD4DMZ
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« Reply #28 on: February 17, 2018, 10:23:13 PM »

At present I am accumulating parts to recap the R2 as it is all original.

Looking at a Phil and Tim's Ranger rebuild sites 1,000 volt ceramic disc caps are recommended in a few spots. I have some of them on hand but not all. My largest ceramic disc cap is .01 mfd.

For instance, one value is a .1 mfd cap and what I have are Sprague 1,000 vdc orange drops. Is the orange drop ok? Also I have some maroon colored drops.

They also recommend much larger values for the electrolytics. I have a supply of many ratings on hand but do not want to go too large. The manual actually has a +100%/-20% spec so the ratings must not be that critical in the HV supplies. To replace the 10 mfd 700 VDC cap I have two 33 mfd caps in series with two 470k ohm flame resistant 1 watt resistors ready to go.

I have 1N4007 diodes on hand and may replace the 6AL5 bias rectifier as that is any easy upgrade. Is that ok to do without replacing the HV tubes as well?

Any advice appreciated.

Thanks, Rich
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KB2WIG
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« Reply #29 on: February 17, 2018, 11:20:01 PM »



Well.... if yer gonna start playing with the boat anchors, your going to need parts....

A quick walk through the Ranger 2 manual  lists  (36), .005  600 volt disc ceramic caps....   You can get 36 caps from Mouser for $7.20 plus shipping. .005 is a common cap, and you'll be well served by purchasing more than you need now. Its easy to spend someone's else money - so I'd suggest that you buy several more of what ever you need, and you'll soon have a nice supply of parts.

But.....

I doubt that any of the ceramic caps in your Ranger need replacing. But if any do need replacing, its nice to have things on hand. When ever I break down and buy parts from Mouser, I'll flesh out the order by buying a few dollars worth of resistors or capacitors- I bought several hundred 1n5408 diodes- The are 1kV, 3 A diodes, and I'll not have to buy any for a while. I pretty much use them anywhere a rectifier is needed (I still have a lot of 1n2007 for things like the 6al5).   And then there's the ham fests.

klc.
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MikeKE0ZUinkcmo
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« Reply #30 on: February 18, 2018, 04:41:04 AM »

I've bought many components just to have on hand.   It's needlessly frustrating to start a project and find I have to put it on hold for some 2 cent part.   As a general rule, ceramic disc caps don't need replacing.

l would recommend you stick with electrolytics and paper caps if you just want to replace something carte blanche.

Quote
...and what I have are Sprague 1,000 vdc orange drops..
Depends on where they are used.  

There is a chart about half way down this page you may find useful, regarding the various capacitor types and the circuit they may be used in.   Of course as in anything electronic, there are other factors to influence your final decision, but this gives a place to start.

If you want to replace the rectifiers, I'd put some series resistance in the string as well, if for no other reason than to  reduce inrush current.   I used 100 Ohm, 5 Watt wire wound resistors, to somewhat compensate for the original tube rectifiers internal voltage drop at the expected load.   A quick look at the tube manual will give you what you need.
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Mike KE0ZU

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WD4DMZ
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« Reply #31 on: February 18, 2018, 08:34:59 AM »

Good morning. Good advice.

I was going to leave the discs in place and replace only electrolytic and paper caps. The question arose because the two R2 rebuild sites I referenced specified 1000 V discs to replace the paper caps. Most of the paper caps in question are rated 400 V or lower so the normal mylar and orange drop caps rated 600 v should be fine.

Everything in the R2 looks good after two weeks of operating it so I am in no hurry to replace anything, just amassing the parts to do it all at one time.

There are many mods listed but I plan to leave it mostly as built so the next owner (decades from now I hope) will have a good example of an R2.

Regards, Rich
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WD4DMZ
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« Reply #32 on: February 18, 2018, 11:30:45 AM »

There is one paper cap that concerns me  - C69 - a 1,600 Volt .02 mfd in the audio circuit. It looks ok but if it were to fail I suspect there could be fireworks. I have seen no reports of one failing but will replace it while I'm in the radio.

Am I over concerned?

Rich
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MikeKE0ZUinkcmo
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« Reply #33 on: February 18, 2018, 05:39:54 PM »

I'd guess the R2 only has one, across the modulator transformer.   Some of the early R1s had two.  Wouldn't hurt while you're in there.
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Mike KE0ZU

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KB2WIG
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« Reply #34 on: February 18, 2018, 06:22:07 PM »



I replace my C69 with a 1600 V , .0022uF Orange drop. 'Cause that's all I had.


klc
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WD4DMZ
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« Reply #35 on: February 18, 2018, 09:14:09 PM »

About 4 years ago a gent I knew passed away suddenly and left his family his huge collection of old radios and TV sets. He also had a large stock of caps and resistors etc. I purchased the small components - many hundreds of well organized pieces - and after going thru the boxes today there was a box of 1600 volt caps. These are made by Mallory in dark maroon (mylar?) so should be good products.

Good news is that there are a few .02, .01 and .068 mfd caps in the mix so I am all set.

If this is not a critical value as WIG noted I may go with the .01 because it is much smaller than the .02.

WIG... Did the .0022 have any bad effects?

Thanks, Rich
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KB2WIG
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« Reply #36 on: February 18, 2018, 10:49:02 PM »



No, not that I'm aware of. If I remember correctly, reducing the capacitance increased the audio frequency response a bit. If you have problems, just tack another .01 across the .01 and yer back to where you started .

I'll add another bit ' advise.  Since you have it working, only make one or two changes/replacements at a time. If you screw up, you'll save a bag of time with only a few things to check. I love my camera ( yeah, I bought a digital cam  around '05 to document what I did.)

klc
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