Radar notes
A radar serial reads the same forwards and backwards — 15788751. Exactly 9,999 of the 99,999,999 serials in a full run qualify, which is 1 in 10,001.
Why 9,999 and not some other number
A palindrome is completely determined by its first four digits: choose those and the last four are forced. That gives 104 = 10,000 possibilities, minus 00000000, which is never issued — a press reaching all zeros produces an error note that is destroyed and replaced with a star note. So 9,999, or one note in every 10,001.
That makes radars the most common fancy serial that anybody actually pays for, and the most recognised. Both facts matter: recognition is what makes a radar easy to sell, and frequency is what keeps the price sensible. Roughly one banknote in ten thousand is a radar, so they turn up in bank straps, change drawers and ATM withdrawals regularly enough that a patient collector can find one without buying it.
The radar family
Four variants sit above a plain radar, and the gap between them is large. A super radar is over a hundred times scarcer than a radar, and a true binary radar — fourteen per run — sits in the same territory as a solid or a ladder.
| Pattern | Example | In a run | Odds | Standing |
|---|---|---|---|---|
| True binary radar Palindrome using only 0 and 1. Fourteen exist in a full run, which is solid-and-ladder territory. | 10100101 | 14 | 1 in 7,142,857 | Trophy |
| Super radar Palindrome whose six interior digits are identical. Often several times a plain radar. | 12222221 | 90 | 1 in 1,111,111 | Major |
| Binary radar repeater Palindrome and repeater at once, on two digits. | 61166116 | 90 | 1 in 1,111,111 | Major |
| Binary radar Palindrome using only two digits. | 83833838 | 630 | 1 in 158,730 | Mid-market |
| Radar Reads the same forwards and backwards. Widely recognised, and common. | 15788751 | 9,999 | 1 in 10,001 | Entry fancy |
What one is worth
Premiums are added to face value rather than multiplied by it, and they fall away fast with handling — these are uncirculated figures. A folded example keeps well under half of this.
| Pattern | $1 note | $20 note | $100 note |
|---|---|---|---|
| True binary radar | $250 – $3,000 | $475 – $5,400 | $750 – $7,900 |
| Super radar | $60 – $400 | $130 – $750 | $250 – $1,100 |
| Binary radar repeater | $60 – $400 | $130 – $750 | $250 – $1,100 |
| Binary radar | $16 – $90 | $45 – $180 | $140 – $325 |
| Radar | $4 – $25 | $25 – $65 | $110 – $165 |
Check a serial for collector patterns — the checker tests all 34 patterns at once and reports every one a serial matches, with the odds for each.
What to look for
- Read the digits in both directions. Only the eight digits count. The prefix and suffix letters are not part of the palindrome, and no collector expects them to be.
- Check the interior. If the six middle digits are all the same, you have a super radar — 90 exist per run rather than 9,999.
- Count the distinct digits. A radar using only two digits is a binary radar; one using only 0 and 1 is a true binary radar, and there are just 14 of those in a full run.
- Condition decides most of the price. A crisp radar and a soft, folded one are not the same sale. The premium, not the note, is what wear destroys.
Questions
What is a radar note?
A radar note is a banknote whose eight serial digits read the same forwards and backwards, like 15788751. The name comes from the word radar, which is itself a palindrome. Collectors also call them palindrome notes.
How rare is a radar serial number?
A palindrome is fully determined by its first four digits, so there are 10,000 of them per run, less 00000000 which is never issued. That is 9,999 radars in 99,999,999 serials, or 1 in 10,001 — roughly one note in every ten thousand.
How much is a radar note worth?
A radar on a $1 in uncirculated condition typically carries a premium of a few dollars to a few tens of dollars. Radars are the most widely recognised fancy serial there is, which makes them easy to sell and keeps the premium modest. A circulated radar pulled from a wallet is usually worth little more than face.
What is a super radar?
A super radar is a palindrome whose six interior digits are all identical, like 12222221. There are only 90 in a full run against 9,999 plain radars, so a super radar is over a hundred times scarcer and sells for a great deal more.
Is a repeater the same as a radar?
No. A repeater has its first four digits repeat as the last four, like 12341234. A radar reverses them, like 12344321. Both occur 9,999 times per run. A serial can be both at once, which is where the binary radar repeater comes from.
The derivation above, and those for every other pattern, are on the methodology page.