Batboard

I would like to modify a 403-433 standard analog spectra VCO to work
at 450. Has anyone attempted this before? D44KMA7JA5BK
Thanks
Dennis

saberjerk wrote:Just wondering if anyone has been able to get an analog spectra
UHF low 406-433 VCO to work into the 450 or so range?
How high can they go?
I haven't even thought about the preselector yet. Not sure that's
even possible.
Did some searching but didn't come up with much.
Thanks
Dennis

I have one and modified the band limits in the RSS, I was able to get it to work fine up to 441.500 Mhz on transmit and receive . After 441.500 the reciever stoped working but it would still transmit up to around 446 mhz. Good luck, I don't think you'll ever get it up to 450 mhz.

Frank

Thanks for the reply Frank.
I guess 441 if pretty good considering the stated upper limit of 433.
Could you go into more of the details of your attempt?

How did you move the VCO? Does it need more trimming or silver paint?

When you mean the receiver quit, do you mean it lost sensitivity or
lost lock?

I appreciate your input.
Thanks
Dennis

saberjerk wrote:Thanks for the reply Frank.
I guess 441 if pretty good considering the stated upper limit of 433.
Could you go into more of the details of your attempt?

How did you move the VCO? Does it need more trimming or silver paint?

When you mean the receiver quit, do you mean it lost sensitivity or
lost lock?

I appreciate your input.
Thanks
Dennis

I did not do any internal mods to the radio, I just hacked the band limits in the RSS and programmed the out of band stuff.
Frank

So.... If someone were to mod the VCO do you think it would be possible
to go up to 450?
I have some 450-480 preselectors. I don't see why they wouldn't work.
I think the PA will need some attention too.
Oh well, a lot of babble.

saberjerk wrote:So.... If someone were to mod the VCO do you think it would be possible
to go up to 450?
I have some 450-480 preselectors. I don't see why they wouldn't work.
I think the PA will need some attention too.
Oh well, a lot of babble.

Damn, all this time I thought we were talking about an Astro Spectra!! The radio i am refering to is an Astro Spertra W3 Q split 403-437mhz.

Sorry about that man.

Frank

Nope. Said very first thing in my posting that this was a plain analog spectra. D44KMA7JA5BK
Shoot I thought those expensive astro's had wider bandwidths than that.
Are you sure they don't go 403-470 like the astro sabers and such?

[quote="saberjerk"]Nope. Said very first thing in my posting that this was a plain analog spectra. D44KMA7JA5BK
Shoot I thought those expensive astro's had wider bandwidths than that.
Are you sure they don't go 403-470 like the astro sabers and such?

No, 403-437Mhz, you did post this in the Astro forum that's probably why I never noticed the analog in the header.

Frank

oops, how did that happen. Thought I was in the general discussion.

I did modify a couple of 403 to 433 PA's to go 440 to 482, but it is a lot of work, and parts.

How about VCO's
Has anyone modified a low split vco to work on 450?

One complication of modding the low split vco to range 2 is the vco steering lines. They will toggle at specific frequencies, (and I cant remember exactly what), and could drive your vco either in or out of lock. I played with this for awhile, and the end result was just not what I wanted. If you modify your range on the command board from range 1 to 2, you can change where the vco steering lines toggle, possibly improving (or not) your end result.

Randy

Well I plan on changing bandsplits on the command board. Is the frequency mod the same for this vco as batlabs shows for the range 3 one?
Has anyone attempted this mod on the range 1 vco???
THanks