Search

Musopen Telford Will Be Moving To A.M.

SignalGuy's picture

Well the first commitment has been made. I've just gotten off the phone, ordered crystal from ICM. 4 weeks lead time. Time to dig out some parts and a soldering iorn!

What did it cost?

What did it cost?

Rich Powers Part15, Take 2..

Pricey

About $72. It's the old style HC-51U. 1700 KHz.

Hobbyist Microbroadcaster in Telford, Pa. Royalty-Free Music from WWW.MUSOPEN.ORG

Excuse my ignorance, but do

Excuse my ignorance, but do you know if that's the same type crystal the Rangemaster uses? I will be in need of another 1700, and Keith doesn't sell them anymore.

Rich Powers Part15, Take 2..

Rangemaster

I will take a guess that the rangemaster uses a much more modern type of crystal. The type I have ordered is quite old, late '50s format HC-51U. They were used in many 1960s "boat-anchor" (large & heavy) ham radio transmitters. As for the Rangemaster, I seem to recall that there is a crystal used as part of a module, and, at least two versions available. That's a very high end Part 15 unit. They took extra steps to assure performance and accuracy. You might be best off getting the module from them. I suppose you could modify one as well, but, I've never worked on a Rangemaster so all this is assumptions and guesses on my part, and, what little I gleaned from their website. Good Luck!

Hobbyist Microbroadcaster in Telford, Pa. Royalty-Free Music from WWW.MUSOPEN.ORG

Mystery signal gone today...

....but will go ahead with AM.

Hobbyist Microbroadcaster in Telford, Pa. Royalty-Free Music from WWW.MUSOPEN.ORG

Keith Hamilton is the

Keith Hamilton is the manufacturer, I asked him last week how much was a 1700 crystal, and he replied "They don’t make the crystals anymore, I sell the adapter for the new modules.". I kind of already knew that, but thought he might have a few left over.

But anyway, good luck with your venture.

Rich Powers Part15, Take 2..

WOW...

...Sure glad ICM is still there! I guess once the tooling & equipment wears out, it will be over. There are plenty of generic DDS circuits to try, but I'm thinking a crystal oscillator would still have the lowest phase noise at these prices. Can you see the existing crystal? Maybe even remove it safely?

Hobbyist Microbroadcaster in Telford, Pa. Royalty-Free Music from WWW.MUSOPEN.ORG

Yeah I can see and easily

Yeah I can see and easily remove it, it's a two pin can, just now from a little google searching I think it's a H6-CU, but not absolutely certain about that. I currently have a 1700 in use and a spare other (1650 or 1660 - I forget offhand), but I might be wanting another 1700.. It really depends on when and if I .. long story, but last year I had been experimenting transmitting with the Rangemaster on a sailboat grounded in salt water of the back river at the south end of the island and was getting mich better range than any previous installs I had, and determined if I could find a good location at the mid point of the island to anchor or dock I could probally cover the entire island fairly well woth one transmitter... but the hurricane about 5 months ago put my boat high and dry on the island across the way only accesible by boat and it's a major problem getting it back to the river.. really all I can hope for is to wait until I have a hunk of change to work with to hire some tug boats or something, right now just cant afford it.

But anyway.. I may decided using two transmitters, one on each side of the island both on 1700.. with some probable dead space between them... I really don't know, I was really liking the sailboat idea, though there were a few cavets with that too.. Regardless of what I end up doing I would like to have a spare 1700 on hand.

 

Rich Powers Part15, Take 2..

Duplicating that crystal.

ICM used to offer a service where you could send them a sample crystal, specify what changes you need, and they could manufacture a new one. I know they are pricey, but, might be worth asking them. Good idea with the salt water "ground plane" ... high maintenance but must have been fun while it lasted. Grounding or counterpoise is going to be an issue for my new install also. Much experimentation awaits me!

Hobbyist Microbroadcaster in Telford, Pa. Royalty-Free Music from WWW.MUSOPEN.ORG

Log in or register to post comments
randomness