fm transmitter

I saw on the instructions that we can hook up a couple resistors on a BNC plug for a fake antenna....but I suppose hooking up a real antenna is just as easy.

Anyone have ideas on the error when programming the PIC?

I'm using the MPLAB IDE software that Sure Electronics recommends. Maybe the 18F1220 is not compatible with the Sure Electronics version of Pickit 2 and Sure's development board?
 
rkhanso said:
I saw on the instructions that we can hook up a couple resistors on a BNC plug for a fake antenna....but I suppose hooking up a real antenna is just as easy.

Anyone have ideas on the error when programming the PIC?

I'm using the MPLAB IDE software that Sure Electronics recommends. Maybe the 18F1220 is not compatible with the Sure Electronics version of Pickit 2 and Sure's development board?
Click to expand...

A load of some type will work fine...just as long as the power has some place to go.

I have programmed anything but the Pics we use. However, I have gotten this error before with my chinese made Pic programmer. Typically, I just try it again. If that does not work, I pull out the Pic, reseat it and go again. One of these items has gotten the job done.

Now, my failure to verify error has almost always been different each time I ran the verify function. I don't know if this helps but that is my experience.

Cheers,
Chris
 
Anyone have a good source or part number for the BNC Cables? I was wondering if they are RG58, RG59, RG6. Is it something easily made with ends and cable or is it better to buy them pre-made?
 
rkhanso said:
Anyone have a good source or part number for the BNC Cables? I was wondering if they are RG58, RG59, RG6. Is it something easily made with ends and cable or is it better to buy them pre-made?
Click to expand...

I bought BNC connectors for my RG6 cable...its a bit stiff but should work
 
okay I am looking for enclosures for these boards now.....

I understand why the xmitter needs a metal enclosure. What about the other boards? My assumption is that they do not produce RF signals for transmission so they should be able to go into a plastic box...correct?

Also, If I do put the xmitter in a plastic box...will foil work to shield it properly?

Thanks,
Chris
 
g2ktcf said:
okay I am looking for enclosures for these boards now.....

I understand why the xmitter needs a metal enclosure. What about the other boards? My assumption is that they do not produce RF signals for transmission so they should be able to go into a plastic box...correct?

Also, If I do put the xmitter in a plastic box...will foil work to shield it properly?

Thanks,
Chris
Click to expand...
Chris,
Look at Tim's post # 113 on this thread. He says it will work but may end up costing more. He mentions copper foil, not aluminum foil.
Roger
 
So far all the extruded Aluminum housings I have seen are $35 each!!! Ouch

This post is ENTIRELY too large...we are now having to repeat ourselves! lol

Cheers,
Chris
 
I wonder if the copper foil found at craft or hardware stores would work to line a plastic box. A question for Tim would be "How thick does it need to be" because some of these are pretty thin.

Or, here are some things I found online.
http://www.defender.com/product.jsp?path=-1|344|301236|69608|303332&id=28788
http://www.westmarine.com/webapp/wc...2?&cid=chanintel&ci_src=14110944&ci_sku=18442
http://cgi.ebay.com/Bare-Metal-Foil-Copper-metal-foil-sheet_W0QQitemZ350164132766QQcmdZViewItem

No endorsement of these companies - just wondering if they'll work.

OR -
It may be a bit overkill, but how about an old PC case.

There may even be enough metal on the cover to bend your own case ---->>> since we are do-it-yourselfers

In a antenna related matter.....I was going to order some BNC connectors from Mouser. I see they come in 50 ohm and 75 ohm versions. Is it important to have all of these match? I was going to make the antenna found HERE. I'll need to get all the connectors shown there, plus the 12 male ends to make 6 cables for the other connections from the transmitter to compressor board.
 
If you haven't used copper foil before be very careful with it - the edges are like razor blades and will slice you up like a Veg-A-Matic... I remember trying to clean up a chassis for FCC/Emissions testing in San Diego and I came out looking like I'd been in a battle...:(
 
budude said:
If you haven't used copper foil before be very careful with it - the edges are like razor blades and will slice you up like a Veg-A-Matic... I remember trying to clean up a chassis for FCC/Emissions testing in San Diego and I came out looking like I'd been in a battle...:(
Click to expand...

Good advice, but there's a really easy solution: get somebody else to do it!!! :lol:

(sorry budude, couldn't resist....)
 
If you guys have a Michaels near by, they have copper foil and screen. In mine it’s over by the wood stuff that’s already put together that you just paint.
 
Would a metallic paint work? There are a few copper-based hobby paints that look like they'll stick to anything since they're not water-based.
 
I've read threads for electric guitars where they have tried the paint to get rid of some of the extra hum but in general they did not get great results (one of those YMMV things...). The good thing about the copper foil is that you can solder the edges up and to your grounds to make it really tight noise-wise.
 
I've still not been able to program the PIC for the compressor board. Searching the help for MPLAB software finds this:
Verify that PIC18FXXJXX, PIC24X, and dsPIC33F devices have an appropriate capacitance on the Vddcore/Vcap pin in accordance with the device data sheet. Some PIC18F devices may require up to 10 uF of capacitance on the Vdd pin to program properly
Click to expand...
Since I have ZERO knowledge about programming (I just click buttons 'til it works) - any ideas how/where I add this capacitor to see if it helps?
 
Well, I got to drilling on my Pira xmitter board tonight. See my blog for pictures. It is two sided and I am very please so far. I realized that I do not have the correct bits for all the holes so I am off to make another list of things to buy. I really hope my wife loves me alot..... lol

Cheers,
Chris
 
A quick couple of questions - maybe I missed it somewhere.

In the instruction manual Tim put together, I don't see R8 (33 ohm) being placed anywhere. Was it an oversight or is it not used?

Also, in the manual C5 is listed as 1 nanofarad, or .001 microfarad, but the BOM listed a .01 microfarad capacitor. Does this matter on this particular cap or was it changed for the modified transmitter?

After many months, I'm finally getting started.

steve
 
Blackbeard said:
A quick couple of questions - maybe I missed it somewhere.

In the instruction manual Tim put together, I don't see R8 (33 ohm) being placed anywhere. Was it an oversight or is it not used?

Also, in the manual C5 is listed as 1 nanofarad, or .001 microfarad, but the BOM listed a .01 microfarad capacitor. Does this matter on this particular cap or was it changed for the modified transmitter?

After many months, I'm finally getting started.

steve
Click to expand...

I do not know of any changes to any of the capacitors. 10 nF versus 1 nf is a big change if that is the case. i have compared the Mouser BOM and the Pira BOM and the 1nf cap is missing.

I ordered directly from Tim's BOMs as well. I am still sorting parts and getting ready to drill and etch my boards. I did see a new post from him on FB and I sent him a message asking him to drop by over here!

Cheers,
Chris


PS...have you done the Encoder and Compressor/Limiter boards yet?
 
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Hi all im new to this forum and found it by chance as I am building the pira 5W FM Transmitter.

What I realy would like to know is, is it imperative that C7, C26 are 10u/35V as I have spare in my junk box 10uf/16V and 10uf/50V would I be able to use either of those instead of the 10uf/35V I asked on the pira forums but recived no answer I also emailed them direct but as yet still recived no answer.

Mine will be the full 7W version as I live in the UK I knowits ilegal but I dont care have ran a 7W VCO transmitter for the last year made it myself using the snakes FM Transmitter.
 
nay27uk said:
Hi all im new to this forum and found it by chance as I am building the pira 5W FM Transmitter.

What I realy would like to know is, is it imperative that C7, C26 are 10u/35V as I have spare in my junk box 10uf/16V and 10uf/50V would I be able to use either of those instead of the 10uf/35V I asked on the pira forums but recived no answer I also emailed them direct but as yet still recived no answer.

Mine will be the full 7W version as I live in the UK I knowits ilegal but I dont care have ran a 7W VCO transmitter for the last year made it myself using the snakes FM Transmitter.
Click to expand...

If it calls for a 10uf/35v, the 10uf/50v would be okay but I'd be a little hesitant to go for the 10uf/16v. It depends on how much voltage *might* go through that cap. That's what the safety margin is for because you don't want one to blow up.
 
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