Got mine yesterday. Going to put it in the big truck this morning and see how it does. The specs were close out of the box. I turned up the AM modulation and wired up a SRA198 mic and the audio sounds great on SSB and AM but as everyone says the audio is a little soft on AM. Not too bad but its not an audio monster thats for damn sure.
Hope propagation does something today as its not been very good arouns here. Id like to get some dx to give it a try.
not my first choice for a mic for that radio,,
just keep an eye on things as the optima radio uses 8v on the audio line to power the factory mic and icom HM-36 style mics,,, there is also another 8v power wire in the connector but its not used
check it out you will have 7-8v on pin 1 and on pin 2
Pin 1 Mic Input
Pin 2 +8VDC
Pin 3 Freq up/dn
Pin 4 NC
Pin 5 PTT
Pin 6 Ground (PTT)
Pin 7 Ground (MIC)
Pin 8 NC
it is wired the same as the icom 8 pin radio's and if you buy an icom 8pin to 4 pin mic adapter they come with a DC current blocking capacitor inline inside the adapter to keep the dc voltage out of the non electret 4 pin mics
I have a clone hm-36 electret mic and the am mod turned up on mine and just last week I went to another town to pick up some stuff a guy had for sale and we met on AM ch15 as I was driving to meet up,,, when I got there he asked and checked out what I was running (optima mk3 and sirio 5000) because he said all the locals in his town run AM radios that are peaked and tuned and mine sounded better that all the guys that he talks to on the radio. he said it was loud and very clear,, he is looking to buy one now
also one more note on the hm-36 original and clone mics,, you need to take them apart and see where the small electret element is mounted,, the mic has 2 locations (front center((where you would normally think the element is)) and center top section) for mounting the element,, if the element is mounted in the top section of the mic and you talk into the front of the mic like where you think the element would be you will not sound great,, but if you talk where the element is mounted you will sound great.