Palomar 300a amplifier

[Tweetybird]

This is fun

 

[Dmans]

I found 100uf 450v axial caps. Are those sufficient?

Those are the values called out in the schematic. They will work fine.
Mine were replaced by the previous owner of the amp. They are radial capacitors and are 120uF @450v.He was "inventive" about getting them mounted physically.

How do you find the white relay you guys were talking about, the potter and brumsfeld one

The picture below is from Nomadradio's post in my 300A "rehab" thread. This would be the only solution I would consider if the relays are bad.

If either or both of the white-plastic "R50" relays has gone bad, we have a drop-in solution for that one.

73
David

 

[Tweetybird]

That really cool i had to look hard to see that

 

[Tweetybird]

Still at a loss for the relays/ numbers.

 

[Tweetybird]

I have 18 guage 600v 150c braided wire. would this be suitable for the old 22 guage replacement? I have the teflon coax and will order the coax connector on the back.this is fun

 

[Dmans]

I have 18 guage 600v 150c braided wire. would this be suitable for the old 22 guage replacement?

I don't see any reason that wouldn't work. I used what I had on hand.
It kept my costs down.

73
David

 

[Dmans]

Still at a loss for the relays/ numbers.

Doubtful you will find those relays new.
A suitable used??? They are too difficult to remove and replace just to "try out" somebody's junk parts.
My opinion is Nomadradio's replacement is a best bet.



73
David

 

[Ranch55]

Those are the values called out in the schematic. They will work fine.
Mine were replaced by the previous owner of the amp. They are radial capacitors and are 120uF @450v.He was "inventive" about getting them mounted physically.
View attachment 31109



The picture below is from Nomadradio's post in my 300A "rehab" thread. This would be the only solution I would consider if the relays are bad.

View attachment 31110

73
David

This is a repair/modification that I did on a Palomar 100 amplifier last year to replace the same relay you are referring to........
It is the small relay ...... Worked perfectly .....

 

[Tweetybird]

Doubtful you will find those relays new.
A suitable used??? They are too difficult to remove and replace just to "try out" somebody's junk parts.
My opinion is Nomadradio's replacement is a best bet.



73
David

I did find new ones. One amp I dont know nomads replacement relay number
.. do you hard wire a dpdt relay in ? I thought the original ones are better if new ? If they are I will buy three more.for the skippers

 

[Tweetybird]

Thanks for helping out .an overhaul is way better than trying to find out what's wrong with a fifty year old amp.

 

[nomadradio]

Certainly more than one way to skin a cat, or to replace an out-of-date relay type.

Our method is just the least labor intensive, IMHO.

Here's our FleaBay listing http://www.ebay.com/itm/113777654146?ssPageName=STRK:MESELX:IT&_trksid=p3984.m1555.l2649

Buying two in one purchase is slightly cheaper. http://www.ebay.com/itm/113755358802?ssPageName=STRK:MESELX:IT&_trksid=p3984.m1555.l2649

73

 

[Tweetybird]

There is an ebay ad for the r 50 relay nib 2 for 11.95

 

[Tweetybird]

Thanks for the link nomad. I may still need it I did buy it on e bay never know some people put their used one in the box their new one came in and sell it.

 

[nomadradio]

An NOS relay will probably work just fine. If it's cheaper, it makes sense to go that way.

We only came up with the substitute board when the prices we were seeing for the original got out of hand.

Bargains do go by on Ebay.

Just gotta act before they go away.

73

 

[Dmans]

There is an ebay ad for the r 50 relay nib 2 for 11.95

Can’t beat that price!

73
David