As many know I have held a TX permit for 8m in the UK.
In the past I have owned an FT-710 which can be put into "engineering mode" by pressing a combination of buttons without the need to uncase the rig and without invalidating the warranty. This allowed TX on 8m, although I never used the FT-710 outside the amateur bands. Instead I used my FT817ND that was widebanded by MLS. On the FT-710 it meant I could TX on 8m if I needed to, but never did.
I am wondering if there is a similar trick with the IC-705 (i.e. just button presses) which would give me TX on the IC-705 at 8m.
I am aware of the diode mod, but do not want to go inside the rig as I no longer trust my fine motor skills!
1 comment:
Hi Roger, just put your question to chatgpt and this is what it thinks: Short answer: No — the IC-705 has no known button-only, externally accessible “engineering mode” or key-sequence trick that enables out-of-band transmit.
And unfortunately, any method that does enable wideband TX on the IC-705 requires internal hardware work (the diode mod).
✔️ What is safe and known
1. The IC-705 does not support an FT-710–style engineering mode
Unlike many Yaesu rigs, Icom rigs — including the IC-705, IC-7300, IC-9700, IC-7610 — do not have hidden key combos that open transmit ranges.
Icom’s architecture ties TX limits to the hardware diode matrix, not to a software flag that the user can toggle.
There is no published or community-verified method to wideband the IC-705 externally.
2. The only known wideband TX mod is the internal diode modification
You’re already aware of this: it requires opening the radio and removing a tiny SMD component.
Given your concerns about fine motor skills, avoiding this is 100% the right call.
3. Keeping the firmware stock maintains your warranty and regulatory compliance
Icom has been particularly strict about maintaining compliance with transmission certifications. They purposely do not provide a user-accessible path to expand TX frequency ranges.
✔️ What you can consider instead
Use an external 8 m-capable transverter
Many operators wanting 8 m TX but leaving HF/6 m rigs unmodified use a transverter.
Advantages:
No radio surgery
Full legality
No chance of bricking the 705
Your 705 stays pristine and warrantable
Examples include:
QRP Labs 50→40 MHz or 28→40 MHz transverters
Acom / Noble Radio 40 MHz transverters
Low-drive SDR transverters (several EU makers)
The IC-705’s clean, low-power drive makes it a great IF radio for a transverter.
✔️ Key takeaway
There is no button-press engineering mode or similar trick to enable 8 m TX on the IC-705.
If you want 8 m transmit without opening the radio, an external transverter is the correct and safe path.
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