Frank ...
I'm happy to report that I now have successfully got a Wireless AP working on an RPi2 and an RPi3 using the Edimax adapter and also using an adapter with a RaLink RT5370 chipset. I have also been successful using the RPi3 built-in wireless.
I followed the instructions you gave earlier in this thread plus 2 additions ...
1) I installed rng-tools because I got an error report about entropy. Did I do wrong?
2) I added 2 lines to /etc/hostapd/hostapd.conf based on advice I saw regarding the RPi3 built-in wireless. My generic hostapd.conf is ...
# interface and driver
interface=wlan0
driver=nl80211
ieee80211n=1
# Comment out following line if using a WIFI adapter with RT5370 chipset
ht_capab=[HT40][SHORT-GI-20][DSSS_CCK-40]
# WIFI-Config
ssid=Rune_AP
channel=11
hw_mode=g
wmm_enabled=1
macaddr_acl=0
auth_algs=1
max_num_sta=10
# WIFI authorization
wpa=2
wpa_key_mgmt=WPA-PSK
wpa_pairwise=TKIP CCMP
rsn_pairwise=CCMP
wpa_passphrase=guglielmo
I've spent many hours getting to this point. My earlier lack of success was a failure to realise the low transmitting power of nano adapters when used as an AP. I had inconsistent results with the RPi 9 metres (plus a brick wall) away from my controlling laptop. When I moved the the RPi to 3 metres away - instant success.
Many thanks for your Wireless AP solution.