UHF Amplifier boards

[burningsuntech]

Hey guys. I have the opportunity to acquire 140 UHF power Amplifier boards which are used in cell phone tower systems. The specifications are: SIZE: 8-7/16 in by 7 in (21.2cm by 17.9cm by 1mm) WEIGHT: 10.1oz (288g). The seller is asking me to quote a price. After doing some math on the amount of gold that could be recovered from the backplane only, thanks to samuel-a's gold calculator and based on the surface area of 59.0625 in, 2 microinches thickness, and gold at an arbitrary $1400 per ounce, I arrive at $1.69 worth of gold per board. There is not much more because the frontside of the board is covered by components.

I have one board as a sample and am asking your opinion on how to process it. Besides the board, there are a few gold plated transistors, some power components, 90 or so 4mm gold pins and one large gold plated TNC connector. Since I am only familiar with AP and not so with AR, would AP be the best approach or let a refiner do the job? What say you?

Thanks for the input. Appreciate this site and your knowledge.

Sam

 

[rusty]

Geo processed similar material - AP http://goldrefiningforum.com/phpBB3/viewtopic.php?f=61&t=18354

 

[burningsuntech]

Thanks rusty.
The board is made of phenolic for obvious reasons. Its cheap and basically a throwaway.
Just for the experience of processing them I offered $3 per pound and was out bid by someone who is really bit by the bug.They offered $6 per pound. I'm walking away. It needs to be fun AND worthwhile for me to bite.

I'm gonna try AP after removing the components and as much solder as possible for an estimate of the gold pulled from it just for the experience.

The experience is worth far more than the gold.

 

[burningsuntech]

** UPDATE **
I chose the AP process but with a twist. Instead of sinking the whole board into solution after removing the components, I divided the board. Using a microplane I shaved the gold covered copper foil off the entire back. With an Xacto knife, I removed only the gold foils visible on the front. Phenolic board doesn't hold onto copper as tenaciously as fiberglass does so you get a very clean peel from the board. This helps in speeding up the reduction time of the copper because it is exposed?
These I processed in AP separate from the remainder of the board which had solder on most of the gold bearing pads. I'm learning that the less junk you add to the batch, the less filtering and chemistry you have to do later.





After cutting the board into 1 inch X 1/4 inch strips, I processed them in a second batch.

I'll process the components later when I learn how to do them correctly so they are off to the storage bin. The pins went into my pin box.

The AP is finished and will be washing, drying and weighing my haul later this week. Just hope I didn't pass up an opportunity to make some change. :/

 

[burningsuntech]

** Math Error **
I finished the board and the AP of the backplane Only. I got .3 grams.
At $1400 per ounce it works out to $13.50 of gold per board. Not $1.69

SO ... I re bid to match the other offer and the seller sold me a 100 Lb lot.

However ... It wasn't just 140 of these boards. It was 8 different boards of varying sizes. Based on the surface area of the Back Only, I estimate 52.5 grams from the lot !!!

Processing this is gonna be FUN !!!