The short answer
**Mount the receiver at the tail of the machine, close to the wheels. Do not mount it inside the
cab.**
That is the result of a controlled test on one reach stacker, not an opinion. The rest of this page
is the measurement behind it.
How we ran this test
One machine, one wheel set, one day. Three configurations, differing only in where the radio
hardware sat:
| Configuration | Repeater position | Receiver position |
|---|---|---|
| A | — | Tail (rear of the machine) |
| B | Front | Tail (rear of the machine) |
| C | Front | Inside the cab |
Every sensor was set to a fixed 2-second transmit interval — the standard configuration, and
also the reason collisions matter (two sensors can land in the same transmit window). Six wheel
positions were monitored in each run, and packet loss was counted the way we always count it: each
sensor increments a counter in the payload, cycling `0x00` to `0x28`, and any gap in that sequence
is a lost packet.
What the data says
| Configuration | Repeater position | Receiver position | Avg packet loss |
|---|---|---|---|
| A | — | Tail (rear) | 8.57% |
| B | Front | Tail (rear) | 7.03% |
| C | Front | Inside the cab | 10.80% |
1. The cab is the worst place for a receiver
10.80% against 7.03% — a 3.77 percentage point penalty for the same machine, same day, same
sensors. The only difference is that the receiver sits inside the cab.
Two reasons, and both are physical:
- The cab is a steel cage. 433.92 MHz does not pass through steel well; a receiver inside a
metal enclosure is listening through a barrier.
- Distance. The wheels are at the corners and the tail; a receiver on the tail is simply closer
to them than one behind the driver's seat.
2. With the receiver at the tail, a front-mounted repeater helps
8.57% down to 7.03% — a 1.54 point improvement. On a long chassis, the front-mounted repeater
bridges the distance between the front wheels and the receiver at the rear. This is what a repeater
is for: not more power, a better listening position.
3. Why this test exists
"Where should I put the receiver?" is the single most common installation question we get — and the
usual answer is a guess based on where the harness happens to end. This is the same answer measured
instead.
What to do with your own machine
1. Receiver at the tail, low and in the open, not in the cab and not behind the dashboard.
2. Front-mounted repeater if the chassis is long — that is where the two ends of the radio link
are furthest apart.
3. Measure the radio path before you commit. The geometry decides, not the specification sheet:
a receiver that passes a desk test can still be three metres and one steel cage away from the
wheels that matter.
What we do not claim
We publish the average packet loss per configuration, not a per-wheel breakdown. One position in one
of the runs read high because every sensor was on a fixed 2-second interval and two transmissions
can collide; that is a test-setup artefact, not a radio result, and we do not use it to argue either
way. If you want to check our numbers, log the CAN data yourself and count the counter gaps — that
is exactly how we produced this table.
FAQ
Should the receiver go where the CAN wiring already is? That is how most installations end up in
the cab, and it costs 3.77 points in this test. Route a short CAN run to the tail instead.
Is a repeater needed if the chassis is short? No. On a compact machine the tail receiver already
sees every wheel.
Does the same answer apply to reach stackers and straddle carriers? The physics does: keep the
receiver low, open and near the wheels. The exact positions differ with the frame.
Can you test our machine geometry? Yes — send the wheel map and the intended receiver position;
we will tell you where the path is short and where it is not.