The mono series is specifically designed to reduce RF interference caused by the colour screen refreshing. It is also highly visible under direct sunlight (when using the light theme).
16 May 2026 Evolution mono890
m7ocm_evolution_i_pcb2.0_uk.bin
m7ocm_evolution_i_pcb2.1_uk.bin
Spectrum now has a blacklist function for nuisance frequencies, max 50 frequencies can be blacklisted during spectrum search.
130.000 is a well known internally generated noise issue as seen above, photo below using the blacklist function to remove it.
To blacklist a frequency press Key 5. To restore all blacklisted frequencies press Key 2.
Blacklisted frequencies persist (in spectrum for the radio session) unless restored or power is cycled.
Key 8 opens the BK4819 register during spectrum - useful to fine tune gain on the fly (active carrier and squelch open).
Key 5 has also been added to the register edit screen globally. That enables/disables AM Fix. This should be off in Spectrum as AM Fix is not suitable for that mode. The indicator AF ON shows when active, when off battery voltage will show.
Squelch line response has been shortened.
VHF airband
8.33kHz logic has been improved in VFO mode so the spacing counts up and down correctly. While VFO 8.33 works perfectly, the spectrum rounds frequencies to the nearest digit. It's not perfect but acceptable given the radios overall performance.
This version does not include NOAA frequencies, only UK MCA MSI channels.
Keyboard commands for new features:
Register Editor
Choose a shortcut key to launch Register Editor or use within spectrum. The screen shows the current register values. The register currently being edited will display in a larger font.
- [Up] Move editor to next register
- [Down] Move to previous register
- [1] Change RF Gain Control (AGC 3, FGC 3/2/1/0/7/6/5/4); If AM Fix is on, use AGC 3 (default). Turn AM Fix off if using FGC
- [2] Decrease value of current register's setting by 1
- [3] Increase value of current register's setting by 1
- [5] AM Fix on/off (should be set off in spectrum)
- [EXIT] Return to main
AGC = Auto Gain Control. FGC = Fixed Gain Control.
FGC is a manual option
LNAS Coarse attenuator (short) LNA Fine tuning attenuator PGA Programmable threshold amplifier MIX Mixer gain BW Bandwidth filter WK Weak signal threshold
Use FGC mode to select exact dB by adjusting the parameters in reg edit
Order is LNAS, LNA, MIX, PGA
0000 ... -98dB
0010 ... -96dB
1000 ... -95dB
0100 ... -93dB
0001 ... -92dB
0110 ... -91dB
0011 ... -90dB
1001 ... -89dB
0120 ... -88dB
1030 ... -87dB
0002 ... -86dB
1120 ... -85dB
0031 ... -84dB
0300 ... -83dB
1130 ... -82dB
1031 ... -81dB
0230 ... -80dB
1201 ... -79dB
0320 ... -78dB
1400 ... -77dB
1131 ... -76dB
0023 ... -75dB
1301 ... -74dB
1600 ... -73dB
0710 ... -72dB
0620 ... -71dB
2131 ... -70dB
0312 ... -69dB
0006 ... -68dB
0521 ... -67dB
0016 ... -66dB
1232 ... -65dB
2113 ... -64dB
1730 ... -63dB
1303 ... -62dB
0125 ... -61dB
2024 ... -60dB
1631 ... -59dB
1205 ... -58dB
2502 ... -57dB
2621 ... -56dB
0523 ... -55dB
2026 ... -54dB
0306 ... -53dB
0604 ... -52dB
0316 ... -51dB
1235 ... -50dB
0515 ... -49dB
0335 ... -48dB
0624 ... -47dB
1524 ... -46dB
3013 ... -45dB
0616 ... -44dB
1525 ... -43dB
0427 ... -42dB
2227 ... -41dB
2524 ... -40dB
2335 ... -39dB
1635 ... -38dB
2516 ... -37dB
3331 ... -36dB
3232 ... -35dB
2526 ... -34dB
3016 ... -33dB
3007 ... -32dB
2536 ... -31dB
3332 ... -30dB
2636 ... -29dB
3205 ... -28dB
3503 ... -27dB
3304 ... -26dB
3117 ... -25dB
3423 ... -24dB
3404 ... -23dB
3207 ... -22dB
3713 ... -21dB
3623 ... -20dB
3533 ... -19dB
3334 ... -18dB
3614 ... -17dB
3605 ... -16dB
3714 ... -15dB
3237 ... -14dB
3534 ... -13dB
3417 ... -12dB
3706 ... -11dB
3517 ... -10dB
3725 ... -9dB
3626 ... -8dB
3536 ... -7dB
3726 ... -6dB
3636 ... -5dB
3537 ... -4dB
3727 ... -3dB
3637 ... -2dB
3737 ... 0dB
Spectrum
- Enter by pressing side key 2 LP (default), reset keys if not
- [Up] Increase frequency range
- [Down] Decrease frequency range
- [1] Change scan step (16, 32, 64 or 128)
- [2] Restore all previously blacklisted frequencies
- [3] Change modulation FM, AM or SB (SSB)
- [4] Change step size (10Hz- 1MHz)
- [5] Blacklist frequency, max 50 per session, restore with key [2], resets on power cycle
- [6] Increase squelch level (response 50ms)
- [7] Hold/Search (in hold, use up/down to adjust main frequency - useful to avoid RFI)
- [8] Enter Reg Edit, [EXIT] to return to spectrum
- [9] Decrease squelch level (response 50ms)
- [0] Toggle VHF/UHF band filter (F = On, X = Off)
- [*] Change scan delay (0 - 12ms)
- [#] Toggle bandwidth (25.0K = wide, 12.5K = narrow)
- [MENU] Jump to VFO mode with current frequency and bandwidth (to allow TX FM only)
- [EXIT] Return to main
- SP [#] switch between VFO-CH mode
Default Keys
- Side Key [1SP] Monitor
- Side Key [1LP] Freq Detect
- Side Key [2SP] Scan/Advance Scan Bank/- Scan Stop (LP)
- Side Key [2LP] Spectrum
SP = Short Press; LP = Long Press
The following keypad keys are all LP
- [1] Step Size
- [2] Modulation
- [3] Bandwidth
- [4] TX Power
- [5] AM Fix
- [6] Dual Watch
- [7] Repeater/Talkaround
- [8] DTMF
- [9] Add or remove a channel to current scan bank
- [0] FMB
- [*] Edit TX Freq
- [#] Lock
- [MENU] Squelch
- [EXIT] Single/Dual Display
End of latest update
20 December 2025 - m7ocm-rt-890-pcb-all-msi-uk-users.zip - UK only MSI edition RT-890 PCB2.0 & PCB2.1
I have removed the NOAA channels/alerts and replaced them with the three VHF MCA HM Coastguard Maritime Safety Information (MSI) broadcast channels: (Ch 62) 160.725, (Ch 63) 160.775 and (Ch 64) 160.825. See here for more information
To use this feature firstly designate a shortcut long press key (eg #5 which is default AM Fix). Select HMCG MSI WX from shortcuts menu. Long press to activate. It will scan these 3 channels until and a broadcast is received. To exit press PTT once.
No other changes, so if you don't care (lol) or use NOAA in the US/Canada, don't download it! I find it useful as I live a few clicks from the North Sea ⛵ Happy Days ⛵
30 Nov 2025 Binary file archive of my recent RT-890 custom firmware for PCB2.0 and PCB2.1. It's the firmware I currently use. Note previous VHF issues with older PCB2.1 firmware was resolved a long time ago (v3.2 on Radtels website). Thanks to Marcus Dudley and Kelvin.
Use at own risk, my personal project, back up SPI before proceeding, no warranty anything works, may destroy your radio etc etc My only advice here is don't expect miracles and expect severe overloading if using external antennas. I use regular whips, and telescopic antennae, I also use bandpass filters, digital attenuators and modest SMA inline attenuators, 10dB is a good choice to knock the edge off on AM. AM mode really needs register changes to get the best out of it - I cannot advise on what may or may not work as your setup will differ greatly from mine.
SATCOM results are good (breaks squelch with decent length telescopic). Experiment with squelch open and edit registers while listening to changes (new feature by dev motorello), better... worse etc its all quite straightforward and resets on reboot so nothing ventured nothing gained is the attitude lol
Other than that its a figure it out yourself approach, I'm afraid, it's what amateur radio is all about right? Strictly no requests, open source available for further tinkering (see credits for the users involved in this project).
When compiling the binary, ensure the correct PCB board is set in the Makefile
- 0 = PCB2.0
- 1 = PCB2.1
Important note, the 10 character name tag font is UPPER CASE English alphanumeric only and special characters/punctuation: . : - = < > @ ? This is a limitation of the standard small font used. No lower case.
No colour versions (shock horror!) strictly mono for reduced interference from screen updates. Works better outside too. RSSI refresh rate reduced to 2000ms, plus a host of great additions from developer motorello 8.33kHz spacing, extended step sizes in the spectrum, reduced long press hold for faster interaction. Standard OEM squelch (sod it, back to basics lol), refined display items for less interference from screen refresh updates. SIGREP (Signal Report/S meter) introduced in single freq mode (OEFWCOM mod - see below), AM Fix indicator in single freq mode.
S meter
- S9 + 70 dB -23 dBm (maxed out)
- S9 + 60 dB -33 dBm
- S9 + 50 dB -43 dBm
- S9 + 40 dB -53 dBm
- S9 + 30 dB -63 dBm
- S9 + 20 dB -73 dBm
- S9 + 10 dB -83 dBm
... note S0-S9 will display as such however S9+ readings will display like this: '9.nn' actual dBm eg (S)9(+).75(dBm)
- S9 -93 dBm
- S8 -99 dBm
- S7 -105 dBm
- S6 -111 dBm
- S5 -117 dBm
- S4 -123 dBm
- S3 -129 dBm
- S2 -135 dBm
- S1 -141 dBm
- S0 -147 dBm
Please see 890 and 890 II repos for additional instructions, M7OCM Chirp driver, Dual Tachyon 890 flasher and SPI restore tools. A lot of the info applies to this firmware but there have been lots of changes (see above for some) since the last update (v3.2 on Radtels website) not least the mono display.
Credits
LCiccio
Marcos
Many thanks to them all, especially Dual Tachyon the legend that reverse engineered the OEM firmware👍
73
M7OCM