Ameritron AL-1500 Upgrade

[nomadradio]

Hi Booker! Welcome aboard.

Tom's board is not the cheapest, but it's the best. Well worth his price. I looked at his web site and didn't find a file with instructions you can download. Gotta figure he includes a diagram showing the hookup.

73

 

[Booker T Polin Jr]

Ok thanks for information Chris

Booker
73 KK4ZDR

 

[Booker T Polin Jr]

I think I have a failed cap on my al- 1500. Haven't taken a look yet . My plan is to order the upgrade kit . Did it come with any kind of instructions ?

Thanks
KK4ZDR

Well I ordered the upgrade board for my Ameritron Al- 1500 from CTR Engineering it arrived about a week ago. So now I am waiting to get it installed. I will have to wait for my technician to get around to it.

KK4ZDR

 

[Ranch55]

Yes, take some photos of the current board and wiring before removing.
You can also label the wires as you disconnect them from the existing board.
If you encounter any issues, don't hesitate to ask.
I did have to make a couple of spacers from 1/4" tubing to remount the timer board, but it wasn't an issue for me. I took some photos I'll post if I can find them.
Good luck. I do believe you will be satisfied.

 

[Ranch55]

Note the "as built" photo, and my upgrade photos with the spacers I cut from 1/4" tubing.

 

[Dmans]

See.
That's what I meant in the other thread. I KNOW you can do it!!

Nice work Ranch55!

73
David

 

[Ranch55]

Thanks David.
I appreciate that.

73's

 

[Booker T Polin Jr]

Yes, take some photos of the current board and wiring before removing.
You can also label the wires as you disconnect them from the existing board.
If you encounter any issues, don't hesitate to ask.
I did have to make a couple of spacers from 1/4" tubing to remount the timer board, but it wasn't an issue for me. I took some photos I'll post if I can find them.
Good luck. I do believe you will be satisfied.

Note the "as built" photo, and my upgrade photos with the spacers I cut from 1/4" tubing.

View attachment 42725 View attachment 42726 View attachment 42727 View attachment 42728 View attachment 42729 View attachment 42730 View attachment 42731 View attachment 42732 View attachment 42733

You done a excellent job I don't think I will attempt this . I will let my technician install it.

KK4ZDR

 

[Crusher]

Nice capacitor bank. Though I wonder why they didn’t use 500V caps for a little more headroom?

 

[nomadradio]

I wonder why they didn’t use 500V caps for a little more headroom?

Cost, pure and simple. The benefit is not so great, but the 500-Volt versions of the same 450-Volt part tend to cost half-again as much more. Adds up when you buy them hundreds at a time. Too much cost for too little benefit.

73

 

[Crusher]

Yeah, I understand the cost part. Only reason I ask, I have seen the AL-1500 transformer used for homebrew. Plate voltage was idling at 4,100+. Less than 50v headroom on each cap seems like it’s cutting it kinda close. That’s all.

 

[nomadradio]

The homebrewer has used the transformer's international-voltage adjust features to goose it way beyond the original intended operating voltage. Using the 90% rule, a supply that idles at 4100 should have total filter-cap rating of 4600 Volts, more or less. Ten of the 450-Volt parts doesn't quite get you there. Ten 500-Volt caps, or a big oil filter would. More than one way to skin a homebrew cat.

73

 

[BJ radionut]

The homebrewer has used the transformer's international-voltage adjust features to goose it way beyond the original intended operating voltage. Using the 90% rule, a supply that idles at 4100 should have total filter-cap rating of 4600 Volts, more or less. Ten of the 450-Volt parts doesn't quite get you there. Ten 500-Volt caps, or a big oil filter would. More than one way to skin a homebrew cat.

73

I always liked what I called the 125 rule... 4100 x 1.25% = 5125 volts on the HV cap range (so 5K+ or better)

 

[Ranch55]

AL-1500 upgraded filter board ..... Tom - W8JI - ctrengineeringinc.com

 

[357]

I was just looking at this and I wanted to say, watch the lead length on the bottom of the board, it should be as flat as the surface and this inductor looks like its dripping something and touching the can, that wire could potentially jump to the can then jump to that inductor. Just something I noticed, could be nothing.
Also I see they used a insulator of some type to prevent arcing from the resistor legs to the can there. thats a potential to break down over time and cause an arc.