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New Viking Valiant Project - New guy is at it again




 
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Author Topic: New Viking Valiant Project - New guy is at it again  (Read 1675 times)
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KC3GMQ
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« on: May 10, 2017, 11:13:35 AM »

Hello again all.  Well the viking II seems to be working well now, so I am jumping in on the Viking Valiant I acquired. Im usually long winded, so If your bored and want to help out a mechanical guy learn this electronic stuff, your assistance is appreciated and most welcome.

So I bought this Valiant, really just paid for shipping... poorly packed and when I opened the box, I got blasted with mercury from the broken 866's.  Ok so they are gone now and I ordered up some 3B28's to replace them.

I was excited to see this is a factory built unit.  That was until I saw someone had there D**K skinners in it and made a gorgeous transmitter look like crap....well in some places.  Maybe I am a bit bold here, but even I with my lack of experience knows not to glob solder on everything.  In places where more then one wire attaches, this person instead of cleaning it up and getting a fresh connection, added a piece of wire as a post and just added wires/cap leads... to that.  Anyway, those are gone as I find them.

*So I gave it a good look over,  the Drive Pot is trashed.  Mouser has one for $50 so I guess thats the price to pay?

*The 866 tube sockets have been replaced.  Rivets  drilled out and only one screw holding each one.  The also are chipped and have carbon tracks.  I will replace these.. should I replace them with the same type, or use porcelain?

* The plate cap wires have been replaced, all are now bad so I am thinking whoever did them last,  used inadequate wire.  The book says to use HV wire, but does not give a size?  Any recommendations on what wire and size to replace the plate wires with?  Also, it has those cheap wire clip plate connectors, should I go with porcelain?

*The variable plate capacitors have a greasy yellow dirty coating on them (smoker?)  Whats the best way to clean these?  Can they be done in place?

* So this has 5 6146 tubes,  how nice lol, In this Valiant, I have a 6146, 6146A's, B's and W's.  WOW.... I wonder if this thing even worked.  I will replace with 6146 or A's but they will all be the same this time.  More money haha.  Socket contacts are all very black,  they are not cleaning up very well so I will replace,  I have a bunch of them already.

*3 other tubes are white inside so they will be replaced also. Starting to think that all the good tubes were pulled out and bad tubes were put in it to get rid of it.

So there you have it for now, My good deal has turned into my next money pit, but it is fun and I am learning.  I want to put this transmitter back to factory condition before I entertain mods.  Any recommendations, comments, help and assistance is encouraged.  Thanks all,  I received awesome help with the Viking II,  made it worth while, looking forward to the Valiant now...

73
Dave
KC3GMQ
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Pete, WA2CWA
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« Reply #1 on: May 10, 2017, 12:57:29 PM »

Hello again all.  Well the viking II seems to be working well now, so I am jumping in on the Viking Valiant I acquired....Thanks all,  I received awesome help with the Viking II,  made it worth wile, looking forward to the Valiant now...

73
Dave
KC3GMQ

It would be nice to explain what you finally did/find/etc. to remedy the 80 meter problem you had with your Viking II thread here: http://amfone.net/Amforum/index.php?topic=42685.200
Don't leave us hanging with that.

Quote
*The 866 tube sockets have been replaced.  Rivets  drilled out and only one screw holding each one.  The also are chipped and have carbon tracks.  I will replace these.. should I replace them with the same type, or use porcine?

I wouldn't use anything porcine. Porcine refers to something morbidly obese.  Smiley
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KC3GMQ
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« Reply #2 on: May 10, 2017, 01:06:56 PM »

I added to it Pete,  not sure it will be an I FOUND IT fix your looking for Smiley
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KC3GMQ
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« Reply #3 on: May 10, 2017, 01:13:33 PM »

I added a reply to my last post
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WBear2GCR
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Brrrr- it's cold in the shack! Fire up the BIG RIG


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« Reply #4 on: May 10, 2017, 02:49:22 PM »

Pictures, in this modern day and age, when accompanying posts are quite useful.

IF the whole rig *smells* of tobacco, I'd certainly wash the whole entire thing, except perhaps for the
meter. If the chassis is all icky/dirty I'd wash it anyway. A high percentage of stuff that comes in here
gets or requires the wash treatment.

There are mods for the drive pot on this forum and/or the "AM Window" Tech section. A search will find much on that rig.

You know about the "Chernobyl Resistor"?

I've been have very good results using ZEP 505 to clean radios. It's better than the other various
assortments of chemicals I've used to remove grunge so far. Lots of water to dilute and remove the cleaner
residue. Then either hot sun for a day or two, or in the cooler weather, around here it's a large fan blowing
a TON of air across it, and flipping the chassis around to make sure there is no pooled water. MUST be BONE DRY
before applying any power.

                          _-_-
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_-_- bear WB2GCR                   http://www.bearlabs.com
KB2WIG
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« Reply #5 on: May 10, 2017, 02:54:20 PM »



"  Then either hot sun for a day or two, or in the cooler weather, around here it's a large fan blowing
a TON of air across it,  "

In the summer time, when the living is easy, stick the washed carcass  into your cars trunk. It's a nice little baking oven in there.

klc

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KC3GMQ
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« Reply #6 on: May 10, 2017, 04:54:17 PM »

I do not know of the "Chernobyl Resistor".  Iv heard about it But where it is, and what to replace it with, or how to get to it, I dont really know...yet Smiley 

The MOD for the Drive pot I think I have, It was designed for the Apache I think but they said you can use it on all the rigs that use that big pot.  It is using a 1 meg pot I think and a few components...am I right.

I will get some Zep 505,  I already replaced a bunch of caps, But that should be ok lol

And here are some pictures,  looks cleaner then it is, and I have been working on it

Dave

* Drive Pot Replacement.docx (382.05 KB - downloaded 19 times.)

* V1.JPG (710.21 KB, 1512x2016 - viewed 90 times.)

* V2.JPG (693.24 KB, 1512x2016 - viewed 90 times.)
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KC3GMQ
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« Reply #7 on: May 10, 2017, 04:55:11 PM »

More Pics


* V3.JPG (645.1 KB, 1512x2016 - viewed 68 times.)

* V4.JPG (514.87 KB, 1512x2016 - viewed 49 times.)

* V5.JPG (806.09 KB, 1512x2016 - viewed 72 times.)
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KC3GMQ
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« Reply #8 on: May 10, 2017, 04:55:59 PM »

And more....


* V6.JPG (709.56 KB, 1512x2016 - viewed 48 times.)

* V7.JPG (667.92 KB, 1512x2016 - viewed 51 times.)

* V8.JPG (712.62 KB, 1512x2016 - viewed 53 times.)
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KC3GMQ
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« Reply #9 on: May 10, 2017, 04:56:42 PM »

and that is it for now Smiley


* V9.JPG (722.48 KB, 1512x2016 - viewed 46 times.)

* V10.JPG (509.27 KB, 1512x2016 - viewed 45 times.)

* V11.JPG (793.3 KB, 1512x2016 - viewed 41 times.)
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N1BCG
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« Reply #10 on: May 10, 2017, 05:46:16 PM »

Looks like you've got a good project at hand.

The tubes with the white dust have broken seals and no longer have a vacuum although all should be tested to be sure.

What's the item plugged into the xtal socket? Two FT-243 xtals can plug in there.

Do you have a variac? I use one and a 150W bulb in series with the line cord for initial testing. Even if there's a dead short, the worse that happens is the bulb lights fully. Even without the variac, there's enough protection to run all the low voltage circuits (everything except xmit).
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KC3GMQ
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« Reply #11 on: May 10, 2017, 05:49:45 PM »

Yes Clark,  I have the same variac set up.  It will be awhile yet though.  I need to sort out the Drive pot, get VFO resister replaced, I need a new 9 pin plug for the back and whatever else I find lol.  No hurry,  Viking II is on the air.  The extal socket has the adapter for 2 crystals.

Dave
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KB2WIG
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« Reply #12 on: May 10, 2017, 05:53:56 PM »


D,


Google "chernobyl resistor" and all will be clear.

Do it for the children.


klc

its the right thing to do.
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N1BCG
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« Reply #13 on: May 10, 2017, 06:01:35 PM »

BTW, those drive pots should be $5, not $50, from Mouser. The Plate leads don't need to be crazy high voltage. Look for reasonably thick insulation. There should be rubber grommets where they pass through the chassis.
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KC3GMQ
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« Reply #14 on: May 10, 2017, 06:09:41 PM »

Ok, I read a couple Chernobyl resistor replace web sites.  Not to bad.  here is my question, In one the guy replaced the 18k with a 20k, and he had a lot of comments saying that was too high.  On wireless girls page, she used a 22k resister and mounted it below the deck.  I saw a few different comments on that too,  dont do it, or yes its best ....  What say you lol.....
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N1BCG
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« Reply #15 on: May 10, 2017, 07:22:43 PM »

That's a dropping resistor between the LVB+ and the voltage regulator tube in the oscillator. Your LVB+ based on today's line voltage is higher so using a slightly higher resistance is fine. I changed mine out with the same 18k but with a higher wattage rating.

Theoretically, a higher resistance value makes sense to keep the voltage regulator tube current within spec.
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KB2WIG
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« Reply #16 on: May 10, 2017, 07:28:13 PM »



D,


You can decide where to place it; I replaced it with a 18K, 10 Watt sand resistor mounted outside the VFO sepulcher.... She'll not go bad with 10 Watt dissipation.

klc
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Pete, WA2CWA
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« Reply #17 on: May 10, 2017, 08:29:49 PM »

There are also stories that the VFO resistor heat dissipation was used somewhat as a "damp chaser" to help minimize VFO drift. Don't really know its truth as my two 18K resistors (in my Ranger and Valiant) are still perking along after 60 years).
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KC4VWU
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« Reply #18 on: May 11, 2017, 03:41:57 AM »

That looks like cake compared to some of the projects I've gotten myself into, but then again, it is a Valiant.

Just take your time, one section at a time. It'll be O.K.
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KC3GMQ
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« Reply #19 on: May 11, 2017, 07:13:56 AM »

Would either one of these work for the Chernobyl resistor, or would one type favored over the other?...

http://www.mouser.com/ProductDetail/Xicon/280-CR10-20K-RC/?qs=sGAEpiMZZMtTURnxoZnJADjPhJRfCLtcSKyhnEegjAw%3d


http://www.mouser.com/ProductDetail/Vishay-Dale/CW01020K00JB12/?qs=sGAEpiMZZMtTURnxoZnJAJ3M9MMlYLtUc18PPXRWkzY%3d
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N1BCG
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« Reply #20 on: May 11, 2017, 07:23:59 AM »

Purists would argue against a wire wound (inductive) resistor in an RF circuit although that one would be bypassed and the levels are very low. I used a 2 watt carbon resistor and that seems fine.

For those choices, both should work with no preference.
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k3msb
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« Reply #21 on: May 11, 2017, 08:23:06 AM »

Hi Dave

You might want to consider these mods for the VFO Chirp:

https://www.w8ji.com/johnson_vfo_chirp_jump.htm

I started on my Valiant in December, but didn't get too far as I put some (more than planned....) time into getting more ARC-5's on the air.   Your work is pushing me to get back to the Valiant.

I removed the side of the VFO cage to remove the Chernobyl resistor, but that's as far as I got. 

I have been warned to be careful when resting the radio upside down;  apparently the shaft coupler for the VFO can be stressed by the front panel in that position and damaged.

BTW,  I'm fairly local to you,  about 45 minutes south down I-83. 






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73 Mark K3MSB
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KC3GMQ
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« Reply #22 on: May 11, 2017, 10:32:28 AM »

Question.... Google failed me. What is an Audio Reactor part L45?Huh


* image.jpeg (272.87 KB, 1287x1289 - viewed 28 times.)
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N1BCG
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« Reply #23 on: May 11, 2017, 10:42:22 AM »

L45 is an inductor (reactor) in an audio clipping circuit. V13 (6AL5) is a dual diode and is used to clip audio peaks, increasing average modulation and loudness. Harmonic energy is generated whenever a waveform is clipped, so a low pass filter (LPF) is used after clippers to prevent the high frequency audio products from causing splatter.

L45 is an inductor that passes lower audio frequencies and appears as a higher resistance to higher frequencies. C94, C95, and L45 make a classic PI filter that's also used in power supplies and output tuned circuits.
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MikeKE0ZUinkcmo
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« Reply #24 on: May 12, 2017, 08:34:49 AM »

You mentioned cleaning the unit, and of course suggestions will be as varied as those offering answers, so here goes.   I use 3 cleaners, Ammonia, mineral spirits, and Acetone.   Ammonia will instantly remove virtually any organic crud, and is one of the main constituents in many cleaners.   The mineral spirits will take many adhesives, some permanent marker notations and any old lubricants and oils, Acetone is sudden death to plastics and virtually all paints, so it should be relegated to the "final solution" position, but will handle just about any petroleum based concoction.

I also use the dish washer on occasion, and often, the pressure washer to make quick work of it all and to get the "big stuff".  Of course, removal of meters, and checking the water solubility of dial markings and other items that can't withstand water are removed, and reasonable care is used to keep water out of the power transformers and chokes.  These are followed by a minimum of a couple days setting on an over turned trash barrel out in the bright sun and breezes.   As I believe some one already noted, the unit has to be bone dry before applying power.




This is what a few spray bottle squirts of Ammonia and a 5 minute pre-soak, followed by a pressure washer episode got me from a pretty grungy looking example.  THIS, or any other item this clean, I won't mind working on.   Not a fan of working on dirty stuff, a habit I picked up 60 years ago working on cars.

Mike
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