I will take one of the transmitter boards .

Arrgh! Ends up Itead Studio gave up their PCB services in 2021 (The last time I ordered was 2020). I bought 250 boards, full service, 1.375" x 2.5" for $138 delivered, or $0.161 per sq in. This was for 2 sided PTH, FR4, 1oz copper, HASL, top and bottom green soldermask and top and bottom silkscreening, no drill size limitations. It did take 3.5 weeks from order to delivery but boards were top notch.

Itead now recommends JLCPCB and putting in your 2.5" x 3.8" dimensions in mm, with the same specs as my Itead boards above, the price with DHL express shipping, 100 boards would be $127 estimated. Eliminating full testing (going to random) and choosing cheaper shipping would decrease the price quite a bit.

Note that I have not used JLCPCB so I can't give an opinion on their quality.

Dave

Thanks for your help on this. Given Colin's experience with the $12 frequency synthesizer, I think he ended up with somewhere around 20 boards. Given only two weeks to gather orders, I'm expecting somewhere between 10 and 20. Point being, there's not much of a quantity discount. Even if someone finds a cheaper deal, it will need to be endorsed by multiple ARF members to change from ExpressPCB.

Two weeks may be limiting, so I'll go ahead and order three for any latecomers.

Current status and projected price:

mjgillen -1
Dale Saukerson 2
eduardoa 3
Mike Yancy 2
battradio@ 1
macrohenry 3

Current total is 12, now down to $14.30 from $21.61. Just eight more and the price is $10.75 (plus my shipping costs to you). Maybe it's time to post an announcement in the Clubhouse where there are often requests to buy AM transmitters.

I'll take a two boards.

Hi Tom,

If you remember, I had 30 boards made by PCBWay in mid September of last year, around the time we had discussions about your project. The cost, including express shipping, came out to be $2.20 per board. The board's dimensions are 3.8" by 2.4", roughly the same as yours. It has white silkscreen, blue solder mask and a different layout to properly segregate the audio, PLL synthesizer and RF modulator section. The circuit is almost identical except for a few differences. The board went through two more revisions since then. So these boards are surplus to me and I'd like to let them go for shipping cost to anyone who wants them. However I do not want to jeopardize your offer. Maybe I just have to let them go to waste.

Cool Project...
I will take Qty 2 PCBs also.

Edit: updated the Parts List in Post #1 with today's prices or substitute part where applicable.
eg if no quantity avail at Digikey, I searched Mouser to see what they had.

If one wants to build the power supply does that mean you'll need two of these boards or is the mains power supply a completely different board?

The transmitter board that I'm ordering takes 12VDC from an external source and is too full of parts to fit a power supply on it. So a second board is needed for an AC power supply if you don't want to use a wall wart or 12 volt battery.

The second version pictured in the OP has a second board that contains the onboard AC power supply AND a compressor/limiter. The onboard power supply I use takes up about 1/3 the space on that size board. I can make available that Express PCB file if anyone wants to make their own board or order elsewhere. That board is single sided and lends itself well to the laser printer toner method. If you don't need the compressor/limiter, you can simply populate a few power supply parts. It's a dual supply consisting of a $7.00 transformer, two resistors, two diodes, two zeners, and two capacitors.

THANKS majortom for updating the price list and including Mouser. I was just going to start that today!


Current status and projected price:

mjgillen -1
Dale Saukerson 2
eduardoa 3
Mike Yancy 2
battradio@ 1
macrohenry 3
processhead 2
majortom 2

Current total is 16, now down from $14.30 to $11.93. Just 4 more and the price is $10.75 (plus my shipping costs to you).

I would like to order one board.

I found three discrepancies in your captured schematic diagram. They are corrected and highlighted by red rectangles. The first two have to do with the BJT base and MOSFET gate circuits. The third has to do with the carry in/enable pin of the CD40103. You have it driven by the VCO output which is fine to do so. The other option is to ground it which is consistent with your layout published earlier.

I'd like to have one of your boards. That brings the number to 18, two short for the next price break.

Thanks for your sharp eyes. I corrected the schematic and replaced the one in the OP. I made corrections a couple of days ago hoping that was the final version. It helps to have others proof read it.

mjgillen -1
Dale Saukerson 2
eduardoa 3
Mike Yancy 2
battradio@ 1
macrohenry 3
processhead 2
majortom 2
markg123 1
bb.odin 1

Current total is 18, now down from $14.30 to $11.93. Just two more and the price is $10.75 (plus my shipping costs to you).

I'll take one board please!

I will also take one board please.

I'll take a board as well. This sounds like a fun project!
Steve

Add me to your list Mac, I'll take one.

I'll take one.

I will take 2 boards.

I will take two boards please, #26 and #27 it seems so far. (-:

I did not see if a parts layout (silkscreen) was planned, but if that is another dollar or two per board as an option, I would vote for it. Thanks!

I'd like to order one please.

Larry

Now down to $10.75/board.

mjgillen 1
Dale Saukerson 2
eduardoa 3
Mike Yancy 2
battradio@ 1
macrohenry 3
processhead 2
majortom 2
markg123 1
bb.odin 1
dacsman 1
Dennis H 1
SeniorSteve 1
Mike Toon 1
Joseph Newton 1
Phil Wiesing 2
ChrisW6ATV 2
rocketeer 2

Current total is 29, price is $10.75 plus prorated share of ExpressPCB shipping to me plus my shipping costs to you.

As we get closer to the May 31 cutoff, I'll post instructions how to send funds and my shipping to you. I'm thinking personal check will be easiest for me to keep up with it all.

As long as we have 20 who want to stick with the $10.75 cost, if the other 9 (or fewer) want to pay more for solder mask and silkscreen, I can compute those costs. For those extras ExpressPCB has a maximum of 10 copies per order. I'll calculate that and post it soon.