Question of the day: Astro Spectra and 2.5 khz VHF

[jmr061]

Ok, I am aware that on the hardware side you are supposed have a HRN6014C or newer RF board. You also need host of 9.xx.xx or higher (I forget the exact number). Well I have tried to do it before with the higher firmware and the A revision board and you get a warning saying it won't program a 2.5 khz channel because of hardware or firmware not being correct.

Well for fun I just upgraded a VHF astro spectra to R11.70 and changed a channel to 2.5khz and programmed it away. It took, no warning message.

Has anyone done this before. I havent tested the radio to see if 2.5 really works in TX but I am shocked that it took it.

Anyone else do this and test it before?

Jason

[tgo]

Jason & board:-

The mid-power Astro Spectra I have did generate a warning message in RSS v8.50 when I tried to program a splinter freq into the radio. This radio had rf board revision "A."
An upgrade to revision "K" took care of it.
I am now using CPS for programming, haven't yet tried it on this feature.

[jmr061]

HHmmmm, maybe it will do 2.5khz but not the splinter freq, what freq generated the warning. Ill try it.

Jason

[tgo]

To the best of my recollection, freq was 156.0525 TX/154.0325 RX.

[jmr061]

Tried that and got the error, oh well.

Jason

[tvsjr]

The old RF decks lacked an oscillator with high enough stability to properly tune the SPLINTER channels, like 155.4675MHz. All VHF Astro Spectras will transmit at 2.5KHz deviation all day long... you must have the newer/higher-stability board to do the splinters.

[motorola_otaku]

the SPLINTER channels, like 155.4675MHz.

Hey, I know that frequency!

While we're on the subject, I discovered (much to my surprise) that an Astro Spectra with an older non-2.5kHz-capable RF board WILL take 6.25-spaced frequencies. So if you only need RX, you can plug in an adjacent 6.25 splinter to your 7.5 target freq (i.e. 155.46875 for 155.4675), set the bandwith to 25kHz, and be close enough to decode P25 audio. I also discovered that all the base station users of that freq in the state transmit an individual ID of 1.