Viking Valiant Cap Wiring question

[N2LK]

Hello, me again. I have started the process of replacing the old electrolytics in this viking but cant wrap
my head around on how to wire in (correctly) the replacement electrolytics for C93A,B and C98A,B.

I have a good copy of the manual now and schematic, but still I am not grasping this, so being a newbie a bit
I am asking the experts.

See photo where I point out in white lines what I am asking. I have 4 wires for C93 and 3 wires on the C98 old caps.
I have 4 new 22mfd - 450V rated caps...how do I wire them in with correct polarity is my question.

Thanks for any responses.
73
John-N2LK

[KC4VWU]

Hi,
      Hope you have radial mount caps and a few terminal strips to make it easier. C 93 is for the bias (V21), which is a negative voltage, so the caps will be wired positive to ground, negatives to the tube socket pins. A terminal strip mounted at that ground lug would allow you to remove the two flying leads from the old cap and connect the POSITIVE leads there, then run the two left over from the tube socket to the NEGATIVE cap leads.

       C 98, for the low voltage (V20), is just wired regularly, pos.to pos., neg. to ground at the ground lug. Again here, a terminal strip would be the easiest way to mount them and allow you to use the positive flying leads from the old cap. This helps by forgoing having to disconnect the leads at the rather obscured tube socket pins and possibly breaking them in the process. That would suck!

Hope this helps.

73, Phil

[N1BCG]

Hi John,

You're definitely doing all the right things for the restoration! The C93A&B caps are for the bias supply so they must be wired with the + leads connected to the chassis. This is the only supply in the transmitter that provides a *negative* voltage. The original C98A&B is a combination capacitor (two in one case) and has a single black lead that connects to the chassis. Your two replacements would both have their - leads connected to the chassis and the + leads would go to the same locations as the original leads.

Post-posting addendum: sorry Phil! Dupe info...

[N2LK]

Funny, after some chores just read again my resources and came to the recommendations you two'
just came back with! Was going to post that I had the answer...very nice to have confirmation, I take this part of the
restore very carefully..

Thanks!
72
John-N2LK

[W6MQI]

Don't wire them in backwards like I did (Dum As*) I'm just glad they didn't blow up and destroy something. What makes me mad is I just rebuilt a Ranger so I should have known Oh well

[N2LK]

New Topic Gents-AC input. I saw bad smoke damage around the ac 2-line cord input and burnt by-pass caps. Tore that part out and have new caps, awaiting terminal strips. Want to wire a 3 prong outlet cord I have. Figure to pull J5 SSB PL connector out and put some type of fusing over there there. I believe I need 2 x 8A fuses.

See photo where I point out my questions.

Any suggestions on accomplishing this as cleanly as possible is appreciated.

73
John-N2LK

[WD8BIL]

John..... since the neutral is tied to ground in the modern breaker panels you'll need only fuse the hot wire. Three wire plugs have an inherent polarization preventing you from plugging the neutral into the hot side.

Early 2 wire rigs fused both leads cause the maker could not control which way the customer inserted the plug.

[W6MQI]

I believe you can get rid of all those useless coils that will help make room for a fuse holder. I also removed all the .005 disc caps replaced with X1 Y2 caps on the AC line. Also installed a inrush current device on the LV side as well.

John..... since the neutral is tied to ground in the modern breaker panels you'll need only fuse the hot wire. Three wire plugs have an inherent polarization preventing you from plugging the neutral into the hot side.

Neutral wire is the large pin, Hot wire is the small pin.

John..... since the neutral is tied to ground in the modern breaker panels

Neutral wires are only grounded at the main entrance panel not at the sub panel. Maybe that's what you were talking about.

[DMOD]

I leave the VHF filter coils in because so much crud can come in over the power lines these days and these coils help to attenuate those RFI intrusions.

Phil - AC0OB

[KB2WIG]

Just to AMplify......  use AC line rated bpass caps, the X1  Y1 type. Good ol' ceramic caps can do all sort of  nasty things in that application.



KLC

[N2LK]

OK, I thought I just had to tie the one HOT Black to a fuse so that is now pretty easy to do via a fues holder in J5.

I am not sure which terminal the Hot lead goes to though. See pic. Is it middle tab or the 'foreground tab".

I have the X1Y2 caps here, just waiting on replacement terminal board to do that part.

This is such great help...
Thanks
73
John-N2LK

[KA2DZT]

You would do yourself a favor by getting rid of all those coils and caps, you don't need them.  They were there to reduce TVI which is not an issue anymore with modern digital TV.

Fuse the black hot lead,  then connect to the line that goes to the on/off switch.  Connect the black wire from the new 3 wire line cord directly to the fuse holder without making any tie point connections anywhere else.

Any modern AC line caps that you may used should be connected after the on/off switch,  but you don't even need those.  Equipment that have power xfmrs don't need any type of AC line caps.  Those AC caps are used in products that have no power xfmrs and run directly off the AC line.

Fred

[N2LK]

OK, power switch (SW7) goes to the bottom terminal post in that pic, so I can now go do this...

I am still buying a little fire extinguisher before I plug this in and flip that switch someday!!

73
John-N2LK

[W6MQI]

I am still buying a little fire extinguisher before I plug this in and flip that switch someday!!

That's why I bring everything up nice a slow with a variac I also put DVM's all over to monitor voltages as the line voltage is increased don't need any surprises.

[N2LK]

Happy Super Bowl Sunday!
I have rewired the AC input with a 3 wire plug, fuse holder in the old SSB jack hole and new bypass caps.

I checked continuity for the power switch and easy to determine where to land the Hot (Black Lead), on terminal closest to you, not the center as previously posted.

I love these boards so wanted to update this topic so no one in future wires the AC based on my incorrect previous post..
See pic...

Now time to rebuild VFO, new rectifier tubes and variac coming soon..
73
John-N2LK

[KA2DZT]

The black lead from the line cord should been wired directly to the fuse first, even if you have to strip back more of the line cord to get enough length.  From what I see you wired it to the line filters first.  Bad move,  what happens if something shorts in the line filters, like one of the caps??

I mentioned in a previous post to wire the line cord that way.  I told you that for a reason.  Most of these early xmtrs came with a line cord that had fuses right in the plug.  So the line cord, once entering the cabinet, could be wired directly to the line filters.  We don't have cords with fuses in the plugs anymore.  So you have to do things differently.

Fred

[N2LK]

Thanks Fred for the reply. The pic is crowded but I do have the Black Hot lead going first to the bottom lug of the fuse holder.
I had to make a splice as you see to get the length to the fuse..then I have that black jumper off the top of fuse tab to the filter...

Appreciate your check though, I need all the advise I can get!
73
John-N2LK

[W3GMS]

Looks like your doing a good job John.  The chassis appears clean as well.  It must have been stored properly!
Joe-W3GMS

[K4RT]

John,

I'm enjoying following your threads.

Good advice that I received here when tackling the 3-line cord / fuse holder wiring for my TX-1 is to solder the black hot lead of the AC line cord to the fuse holder lug that connects to the fuse at the rear of the holder so that the voltage is kept off the end of the fuse you grasp to remove or insert it.

73,
Brad K4RT

[N2LK]

That is a good piece of advise...will switch the leads....

the last piece to reassemble is the VFO. That is going to be a slow, cautious process as well...I had to
tear it down to fix a coupler problem, Major headache but progressing.

Keep you posted (no pun intended ) as I go.
73
John-N2LK

[N2LK]

The biggest stumbling block on this refurb as been a PITA VFO Cap coupler that i just could not remove!
I tried all the suggestions given to me on another thread here and no luck. Spent 2 days (not full, have to work!) trying to
extract that one small nut from the coupler, new drill bits just made a divit, never could cut into it well.

I knew if I kept trying I would break this cap/shaft so instead I bent the 2 arms out and cut out the 2 little pop rivets on the coupler.
This left 2 open holes and bent the arms back..solid...a fellow on Ebay has a little plastic coupler piece for the Valiant so that will fix that little headache.

With VFO now apart I saw all the black tarnish on wafer switch and cap spring connections so took the opportunity to clean
that all up. New 18K x 5 watt resistor coming too with colored 20ga. tinned wire for rewiring. I will go SLOW in rebuilding this with help from
the construction manual from BAMA....

All electrolytics, paper caps are replaced. new AC input with fuse, cleaned up, just go 2 new 3B28 tubes today. New Variac on order for when I do repower this mighty beast..

Again I couldn't do this without all the great advise here...thanks.
73
John-N2LK