Not sure there is such a thing as upside-down for a vertical yagi. The whole element is "driven" - not just the half with the gamma match. Vertical yagis are best mounted on a non-metallic mast or rear mounted behind the reflector, but a metallic mast through the middle of the antenna may not be total disaster, as the mast will not normally be resonant.

It's worth remembering that cable loss is reciprocal - you lose exactly the same "amount" of signal on receive as you do on transmit. Say you hear a station who is running 50 watts and they are S7 with you. If you call them with your rig set to 50 watts they should also hear you at S7. With lower loss cable you may hear the same station at S8, and then he should receive you at S8 also. As long as you can hear the stations you want to work, they will hear you too, assuming power levels are the same.

I was thinking 70dB was a typical isolation figure (http://www.radioworld.co.uk/catalog/cx-201n_global_2-way_coax_switch_n-type-p-4198.html?osCsid=5126f7572c4b3fd0a2b0113d55ea2f7d) and I hadn't considered an amplifier. Perhaps I should have said that a good quality switch and 100 watts should be fine.

Should be fine - I'm sure many people use them that way - although I wouldn't transmit whilst another receiver or transceiver was switched on. There may be enough isolation between ports but personally I wouldn't risk it.

Do double check the squelch and RF gain settings, as described in the manual. They are the most likely cause of no sound. Also disconnect all accessories - morse key, external speaker, computer CAT control, PTT footswitch - if you have any. Accidentally having the radio in TX mode is another sure way to have no sound on RX. Let us know how you get on.

Anyone know if the monitor level can be adjusted on the Yaesu FT-450? I have the original model, not the AT or D. I use the rig on SSTV and like to have the monitor on when TXing but find the audio level rather low. I am modulating the rig to around 75 watts on SSTV so I would expect to hear the tones at a reasonable level on the monitor. There does't seem to be a menu function to set it; any ideas?

Thanks and 73, Paul G4IJE.

EDIT: Obviously I can turn up the volume (AF gain) to increase the monitor level, but that means fiddling with it between TX and RX which is a pain ...

Sounds like you have a ground loop (or "earth loop" as we'd probably say on this side of the pond). As we are talking about an audio ground and not a safety ground here, you could try just disconnecting the shield on one end of your audio cable. It might seem counter-intuitive but it often works.

The data I found on the Kenwood website says the auto ATU handles up to 3:1 SWR. Handling 10:1 would be pretty amazing for an internal ATU. I think you are expecting too much.

IMHO a 25 amp supply would be fine. After all, that's what they are made for - powering a typical 100 watt transceiver. I've owned several 100 watt HF rigs over the years and don't recall any of them taking more than about 18 amps "key down".

Send QRL? If there's no reply you are good to go.

That is impressive! Thanks for sharing the link.

This is a bit generic but it may help: In Windows 7 right-click the speaker icon, click Recording Devices then double-click on the icon of the relevant device (or click it once and then click properties). On the Properties page is a tab called "Listen" which has a checkbox called "Listen to this device". Remove the check mark. If that doesn't work then there may be some other monitor or "loopback" option specific to your sound card.

It might be worth trying to install the supplied driver rather than the one that Windows Update found. I bought a cheap USB interface cable from Hong Kong for my Quansheng radio and the USB driver supplied on the mini-CD worked perfectly under Windows 7 64-bit. I didn't try the actual programming software on the mini-CD as there was a more up-to-date one to download.

Although it's unlikely your interface is the same, you can download the driver software that came with mine if you want to try it:

http://www.classicsstv.com/temp/win7.zip

With respect to 'RZP and 'BYU, I would slightly modify their suggestion by saying you should switch between a 50 ohm resistive load and the antenna. Listen with a sensible SSB bandwidth selected and any DSP options switched OFF. If you hear more noise from the antenna than from the dummy load, you don't need a preamp.

None really, unless you replace the coax with ladder-line.