So... it turns out that the Midland G18 radio isn't compatible with the Earmor PTT. I haven't had a definite answer on this - I've simply tried two different Earmor PTTs and neither worked with the G18 handset, which is good enough evidence for me (I checked the seal between the 2-pin connector and the handset on both occasions and it was snug, so I don't think this is the same issue as reported by
@Monkman... but thanks again for the heads up on that).
As a Plan B I've bought a Kenwood version of the Earmor PTT to work with a Baofeng UV-5R (which I already had) and to 'ease my conscience' I've also picked up a PMR446-compliant
Retevis RT24 - cheap, cheerful and Kenwood/Earmor compatible, making it what appears to be a license-free equivalent of the Baofeng. I've yet to test it, but reviews seem promising.
As ever, this has proved to be vastly more faffy than I had envisaged. But I seem to have got there in the end, if only through trial and error ?
PS: my Midland G18 is now up for sale if anyone's interested. It's a great quality radio - waterproof and extremely rugged. Might end up keeping it myself for general-purpose hiking and biking use.
For anyone who might stumble on this thread at a later date, here's the list of Earmor PTT-compatible radios: Motorola and Kenwood versions. You can find lists for other connector types on the product listings over at
http://emperionstore.com and elsewhere.
Earmor PTT - list of compatible radios that use the Motorola 2-prong connector:
* XTN Series: XTN446, XTN500, XTN600
* XTN XV Series: XV1100, XV2100, XV2600, XV4100
* XTN XU Series: XU1100, XU2100, XU2600, XU4100
* XTN AX Series: AXV5100, AXU4100
* CLS Series: CLS1110, CLS1410, CLS1413, CLS1450, CLS1450C, CLS1450CB, VL50
* Spirit Series: SV10, SV11, SV11D, SV21, SV12, SV22, SV22C, SU210, SU22, SU22C, SU220, Spirit Pro, Spirit Pro+, HP10
* Spirit MU Series: MU11, MU11C, MU11CV, MU12, MU12C, MU12CV, MU21C, MU21CV, MU22CVS, MU24CV, MU24CVS, MU24CVST
* Spirit MV Series: MV11, MV11C, MV11CV, MV12, MV12CV, MV21C, MV21CV, MV22, MV22CV, MV24CVS
* CP Series: CP88, CP040. CP100, CP110, CP125, CP150, CP200, CP250, CP300
* GP Series: GP2000 , GP2100, GP300, GP308, GP68, GP88, GP88S
* SP Series: SP10, SP21, SP50+, SP50
* CT Series: CT150, CT250, CT450, CT450LS
* P Series: P040, P080, P110, P1225, P1225LS
* DTR Series: DTR410, DTR550, DTR610, DTR650
* Other Series: GTI, GTX, LTS2000, VL130, PMR446, ECP100, PR400, MagOne BPR400, EP450, AU1200, AV1200
* RDX Series: RDV-5100, RDV2020, RDU2020, RDU2080DD, RDU4100, RDU4160D, RDV2080D, RDV5100
Earmor PTT - list of compatible radios that use the Kenwood connector (NB: of this list, only the Retevis RT24 is PMR446 license-free).
Kenwood: TH-F6/F6A/D/D7A/D7AG/D7E/F/F7E/G71/G71A/G71E/K2/K2A/K2E/ K2ET/21/ 21AT/21BT/22/22A/22AT/22E/25/26/27/28/31AT/31BT/41AT/41BT/42/42A/ 42AT/2E/45/46/47/215/225/235/235A/235E/315/415 TK-208/220/240/240D/248/250/260/260/270/370G/372G/373G/320/340/340D/348/350/ 378/378G/430/431/353/360/2100/2102/2130/2160/3100/3101/3102/3107/3118/3130/3131/3160 etc
Kenwood:TK-2170/3170/2312/3312/2360/3360/2400/3400/2400V/3400U/2402/3402/2402V/3402U/3173
Kenwood ProTalk :TK-2400VP, TK-3400UP, TK-3230XLS
Kenwood:TH-F6A, TH-D72A, TH-K20A
Kenwood:Nexedge NX-220, NX-320, NX-240V, NX-340U, NX-420
Baofeng: UV-Series,UV-3R PLUS, UV-5R/5RA/5RB/5RD/5RE/5R V2+/5R5/5X5R+ Plus/8/8D/B5/B/82HP/82L/82/82C/89 BF-480/490/320/V6/520/530/999/888/777/666S/777S/888S/gt-3tp/bf-f9-v2hp+
WOUXUN: KG-UV1D/KG-UV2D/UVDIP/KG-669/659/679/689/639/699/801/kg-uv8e
QUANSHENG: TG-K4AT/2AT/22AT/45AT/42AT/25AT/UV
HYT:TC286 386 2685 3865 6685, TC 278 378 388, TC 2100 2088
TYT 2 Pin
Retevis:H-777,RT1, RT2,RT3, RT5, RT7, RT-5R,RT-5RV,RT-B6,888s, RT24
Linton:LT-2288/3288/6288/5288/3188/2188/3260/2268/3268/6288/6188/3288A
PUXING Radio: PX-666/777/777 PLUS/3288/-888
Hytera Radio:TC-268/268S/270/270S/368/368S//370/370S
WEIERWEI:VEV-3288S/6288/3288