BTW, the ban is on VFR not GA.
More specifically, the ban is on VFR traffic with a mandatory active mode-S transponder. However if your aircraft is exempt from the requirement to carry mode-S (gliders, motorized traffic below 1200') the ban apparently does not apply to you. Regardless of whether you actually have mode-S or not. Furthermore, if there's a rule that forbids you from using your transponder you're also exempted.
At least, this is how I read the highly ambiguous wording.
This is the Dutch AIP GEN 1.5 (Aircraft instrument requirements):
4 SSR TRANSPONDER
4.1 Elementary surveillance
Aircraft shall be equipped with a mode S transponder with elementary surveillance (ELS) functionality. The equipment must be in accordance with the technical specifications laid down in ICAO Annex 10, volume IV, amendment 77.
Activation of mode A/C transponders is prohibited in the Amsterdam FIR.
Exempted from the mandatory carriage of a mode S transponder are:
* motorised VFR flights in class G airspace below 1200 ft AMSL (excluding the NSAA, see ENR 2.2).
* non-motorised aircraft (gliders, hanggliders, parasailers or balloons) outside the transponder mandatory zones (TMZ) and NSAA, see ENR 2.2.
Carriage of a mode S transponder is strongly recommended in the UK North Sea area V, this recommendation is published in the UK AIP and regulation.
This is Dutch AIP ENR 1.6 (Radar Services):
2 SECONDARY SURVEILLANCE RADAR (SSR)
2.1 Transponder operating procedures
2.1.1 Normal procedures
1. The provisions of ICAO (Aircraft Operations Volume I, Flight Procedures, part VIII, chapter 1) apply.
2. Except when conditions in item c and d are met, pilots shall operate transponders in accordance with ATC instructions. In particular, when entering the Amsterdam FIR, pilots who have already received specific instructions from ATC concerning the setting of the transponder shall maintain that setting until otherwise instructed.
3. IFR flights about to enter the Amsterdam FIR who have not received specific instructions from ATC concerning the setting of the transponder shall operate the transponder on mode A code 2000 before entry and maintain that code setting until otherwise instructed.
4. VFR flights in the Amsterdam FIR shall activate their mode S transponder and select mode A code 7000 unless otherwise instructed, except below Schiphol TMA 1.
5. Gliders starting with the use of a winch are advised to activate the transponder only after the winch is disconnected. The high climb-rate during a winch-start can lead to unwanted “resolution advisory” warnings on ACAS systems.
6. In accordance with ICAO Doc 8168 (PANS-OPS) Volume I, part VIII, 1.3; the flight crew of aircraft equipped with mode S transponders shall set the aircraft identification in the transponder. This setting shall correspond to the aircraft identification specified in item 7 of the ICAO flight plan, or, if no flight plan has been filed, the aircraft registration. In order to be interpreted properly, there must be no spaces between the designator letters and flight number, nor any additional/superfluous zeros preceding the flight number. For details see ENR 1.10 FLIGHT PLANNING, 3.2.1 ITEM 7: aircraft identification.
7. In case the aircraft identification can be entered manually, entry should be part of the start-up procedures.
8. Correct setting of aircraft identification is essential for identification and correlation (of radar track with flight plan data). An incorrect setting of the aircraft identification will be reported to the Dutch aviation authorities.
And here's the wording of the AIP Supplement that's active as of today:
The SRZ Schiphol is prohibited for all VFR traffic with mandatory active mode S transponder from GND to
1500 ft AMSL and active H24.
(For those not familiar with the area, the SRZ lies fully beneath the Schiphol TMA 1.)
So I'm a VFR pilot flying below 1200' in an aircraft that happens to be equipped with a mode-S transponder but according to GEN 1.5 carriage of a transponder is not required. I'm flying underneath the TMA 1, so my transponder is off according to the regulations in ENR 1.6. I intend to enter the SRZ. Legal or not?