Astro Spectra "RKH" HAM Out of Band issue

[2wayfreq]

I have an Astro Spectra T04RKH9PW9AN. The model decoder shows it to be 438-482. Astro 9.5 says its 450-482 and wont allow 440 entry. But 5.3 CPS lets me enter the 440 frequencies, but when I go to write it, it complains that I'm about to program the radio "Out of Band" and degrade the performance of the radio. I don't get it. Is it Ham capable or not?

Flash 550008-080400-4
R11.25.00
I 08.03.02
CntrlH D24

I would really like to have a Digital Spectra that can work on 440 Ham. E-bay is kinda barren of 440 Spectras at the moment.

[Pj]

Thought I don't have the ASTRO Spectra manual handy at the moment, I've had no problem with 450 radios going down to 440 for the most part. As some parts have certain tolerances, how far down you can go from the actual rated split varies a little bit per radio. The CPS warning is normal... its just say what I wrote - the radio will take it, but you may or may not get the performance you want.

I've actually had an 450-520 ASTRO Saber that would RX lock 403-520. Never put it on the meter, but it would TX without giving a fail code thru various test freq's. Should have kept that radio.

[N4KVE]

Spectras, or Astro Spectras have a split of either 438-470, or 450-482, but not 438-482 mhz. The entire UHF band is divided into 4 splits on UHF, while Astro Sabers can do the whole UHF band in 2 splits. The Spectra & Astro Spectra have very tight front ends, & depending on the tolerance of front end components used, the receiver of a 450-482 radio will unlock below 446 mhz. Even if the VCO is played with, the receiver will start to go deaf below 446 mhz. It took me several years to locate a few 438-470 mhz Spectras, but they do receive great at 442 mhz. There have been people on this forum who have married 438-470 Spectras to 403-433 Astro Spectras to make a 438-470 mhz Astro Spectra. GARY N4KVE

[2wayfreq]

Thanks Guys,
Well, I'll give it a whirl and see how well it performs on our local repeater.

[motorola_otaku]

Same rules about the VCO lock and RX preselector dropoff apply to Range 3 450-482 Astro Spectras as their analog counterparts. Some will lock down to 441 MHz as-is, others won't. If they don't the same VCO mods used on the analog Spectra can be used, or you can rob a VCO from an analog Spectra that works and do a full alignment. Receive sensitivity is hit-or-miss but generally degrades down to .5 or .6 microvolts down around 442 MHz versus .19-.23 in-band. Again, you can harvest a preselector from an analog radio if it works better - they're 100% identical.

Bandsplit hacking RSS 9.05 is super easy: open ASTROM.ODB with Hex Workshop, look for "450.0000" in plain text, and change it to "440.0000", no checksumming needed.

What you will not get under any circumstances is P25 transmit. For that you absolutely need a 438-470 motorcycle radio or an XTL. Problem is IMBE deviation drops way off below 450 MHz to the point where the receiving radio doesn't even recognize it as P25. Receive works just fine, however. There were codeplugs with deviation softpots down below 450 that corrected this floating around out there for a while, but the people who had them didn't want to share so *shrug*

[d119]

Same rules about the VCO lock and RX preselector dropoff apply to Range 3 450-482 Astro Spectras as their analog counterparts. Some will lock down to 441 MHz as-is, others won't. If they don't the same VCO mods used on the analog Spectra can be used, or you can rob a VCO from an analog Spectra that works and do a full alignment. Receive sensitivity is hit-or-miss but generally degrades down to .5 or .6 microvolts down around 442 MHz versus .19-.23 in-band. Again, you can harvest a preselector from an analog radio if it works better - they're 100% identical.

Bandsplit hacking RSS 9.05 is super easy: open ASTROM.ODB with Hex Workshop, look for "450.0000" in plain text, and change it to "440.0000", no checksumming needed.

What you will not get under any circumstances is P25 transmit. For that you absolutely need a 438-470 motorcycle radio or an XTL. Problem is IMBE deviation drops way off below 450 MHz to the point where the receiving radio doesn't even recognize it as P25. Receive works just fine, however. There were codeplugs with deviation softpots down below 450 that corrected this floating around out there for a while, but the people who had them didn't want to share so *shrug*

That's what I need. I have a 453-488MHz W4 Astro Spectra that I worked on the VCO on to get it to work 438-470. Works great in analog, but there are no soft pots below 453MHz.

I have a working 438-470MHz Astro Spectra, but it's a W9 and I'd like to stick with the W4 I have, or W5/W7 if thats all I can get... But as motorola_otaku said, the S-Records are the issue.