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THE AM BULLETIN BOARD => Military Amateur Radio Section => Topic started by: KI4YAN on March 22, 2018, 11:03:39 PM



Title: BC-659 to 10M FM?
Post by: KI4YAN on March 22, 2018, 11:03:39 PM
I've got this BC-659 that has xtals fitted for the 10M national FM calling frequency-but I have no other information on it. I haven't got the power supply, but I do have the battery case. Is this worth anything to finish the conversion? I haven't ever used 10M, let alone FM mode on it.

Supposedly it'll do 4W output. I have no idea if it actually works, although it's in very good condition internally.


Title: Re: BC-659 to 10M FM?
Post by: Opcom on March 22, 2018, 11:44:16 PM
Lots of low voltage filaments.. Be sure to check all resistors and caps in the filament supply so that too much voltage does not appear on a filament. Sure it's worth fixing up, why not? If 4W is not enough, there are cheap amps for 10M, and some with low noise preamps.


Title: Re: BC-659 to 10M FM?
Post by: PA0NVD on March 23, 2018, 12:15:48 AM
I have a SEM35, a 1 watt German set with (unfortunately) transistors. Nice little dry battery powered set with a whip antenna. I used it at 10 meters FM and had an excelent (noise free) contact from the south of Spain to Stockholm, almost 3000 kM using the whip
I think you will enjoy it, especially when the sun is more active.


Title: Re: BC-659 to 10M FM?
Post by: WA1LGQ on July 02, 2018, 12:19:10 PM
10M FM is fun, its a good local thing, and gets crazy when the band is open. You probably will want to amplify it. Back in the converted CB days we used CB amplfiers with low pass filters added. They did not have any kind of filtering. I wish there was more activity in my area.
Larry


Title: Re: BC-659 to 10M FM?
Post by: WB6NVH on July 14, 2018, 01:52:44 AM
I have the same rig with (I think) 29.6 and 29.5 in it and have the same plans.

However...some issues rear their ugly heads.  The deviation on these is going to be in excess of 20 kHz.  Modern FM systems use +/- 5 kHz.  You may be outside the passband of potential contacts.  The receivers on these, assuming they are on a par with the contemporary BC-603 / 683 tank/artillery sets will be broad as a barn door.

When 10 was last open, the entire 10 Meter FM allocation came in all at once on my BC-683 regardless of how the receiver was tuned, and all you heard most of the time was a pile of heterodynes.  You may wind up being limited to talking to other BC-659's when the band is otherwise dead, on those frequencies!
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