Kit Review
Documentation: 15 pages including change notices, general description, theory
of operation, construction procedure, setup and programming instructions, block
diagram, complete schematics, coil winding details, parts identification chart,
parts placement diagram, troubleshooting hints, antenna ideas and enclosure tips.
Quality of Components: Top quality epoxy board with sliver plated traces and
silk-screen printed part locations. There are also several test points for signal troubleshooting
and educational purposes. The parts were all of good quality. The picture on
the website showed sockets for all the ic's, but you'll have to buy those yourself
as none came with the kit. There was one missing 100pf capacitor.
Quality of Design: Stable and quiet PLL design using eight ic devices and five
Transistors based around the MC145151-2 Motorola chip. Programming is via a
10 position dipswitch, no pic processor or lcd display needed here. A frequency
programming chart is included and the unit can do either 100khz or 200khz
channel spacing depending on a placement of a jumper.
Ease of Assembly: Read all the documents before you start! The change notice
and other notes provided must be followed for the unit to function. Parts
placement is easy with both the board being labeled and the documents provided
clearly showing you what goes where. The biggest challenge was the making of
the tapped VCO coil, this took a little practice to get it right. The kit includes
plenty of extra wire, incase you have trouble. This is not a kit for beginners.
Setup and Use: Alignment was easy using a scope and vtvm for adjustments. The
unit will function fine without test gear by setting the adjustments mid range
and using a stereo receiver for testing. The unit was out of lock when I first
powered it up, but backing out the VCO slug slightly (per directions provided)
brought it in solid. After alignment, I placed a drop of beeswax over the coil
to keep the slug in the correct position. The reference oscillator was off in
frequency about 2khz high, but adding a 10pf cap across the trimmer brought the
oscillator to the exact frequency. This error was so slight, it would not effect
the operation in any way, but since I had a frequency counter, I was being picky.
The power output in part 15 mode was 10 mw and in export mode was 110 mw. The
stereo separation was good and the sound quality was great. No hiss, noise or
other audible artifacts were present in the signal. The frequency remained
stable and did not drift more then 200hz during hours of operation.
Support from Vendor: I emailed a query to support, regarding some of the level
adjustments and I had a courteous and detailed reply in under 2 hours!
Cost: I purchased the unit direct from the manufacturer's website for $89.50 total
shipped. The unit arrived via priority mail in 3 days! (apr 2005)
Link: North Country Radio - FM/Misc Kits & Modules
Rating: ... ............
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