Re: [Elecraft] OT: USB and LSB - How we got there

```Ken and all,

```
BUT, that information is incorrect. The sidebands will NOT invert with a 9 MHz IF and a 5 MHz VFO.

```
A little simple math should convince you.
```
Assume a 9.000 MHz IF and a 5.200 MHz VFO and a modulating frequency of 1kHz.
```
9.000 + 5.200 = 14.200 for the carrier frequency
9.001 + 5.200 = 14.201 for the modulated frequency.  That is Upper Sideband.

9.000 - 5.200 = 3.800 for the carrier frequency
9.001 - 5.200 = 3.800 for the modulated frequency - that is also USB.

```
The early SSB generators (Central Electronics 10A for one) did use a 9 MHz SSB generator frequency, but there was a switch to change sidebands.
```
```
If you have a 5 MHz IF with a 9MHz VFO as was used by Hallicrafters, the sidebands will invert between 75 and 20 meters. Try the addition and subtraction to convince yourself.
```
73,
Don W3FPR

On 2/14/2018 3:08 PM, Ken G Kopp wrote:
```
```Here's a URL to a website with lots of information:

http://www.ac6v.com/73.htm#LSB

Or, search "BC-458 command set transmitter" and
"Central Electronics 10A" with your browser.

```
```______________________________________________________________
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