[TenTec] Dirty Transmitters - Flex and Yaesu

[Jim Brown]

On Wed,12/9/2015 4:34 PM, terry foskey via TenTec wrote:
>   Jim,I am in engineering, questioning why and developing designs, it's what I do. I have commercial and Amateur licenses. The rule you provide for Ham operations is true, however, the passage can be interpreted many ways and I stand my statement there is no specific rule being violated.

It is, but you're looking for a number. The rule is written so that the 
"number" is dictated by the state of the art. It allows the Rules to 
progress with developments in ham radio manufacturing. I serve on an 
international standards committee, and we have written Standards in 
exactly that way, and for that exact reason.

Elecraft has set the state of the art with an expensive rig, Kenwood has 
further defined it with a moderately priced rig. I would thus define 
what Kenwood has done as "the state of the art" for the masses.

>   What we consider dirty today is light years better than the transmitters of old.

Which is why the Rules are written as they are.

> Regarding performing real world operational tests, I have conducted enough operational tests on US combat aircraft and been involved with testing of US Navy vessels to know that labs and real world aren't the same.  Many factors come into play regarding the real effects described as coming from dirty transmitters, such as quality of receiver front ends,

Nope. The quality of receiver front ends is part of the SYSTEM, but not 
part of the transmitter. We're talking TRANSMITTERS.
>   mode of operation (your bandwidth FCC quote comes into play), etc.

I suggest that you borrow a K3 with a P3 and start looking at real 
signals on the air.  On SSB band, you'll see signals splattering above 
and below what should be a 2.8 kHz wide bandwidth (I'm not talking ESSB, 
I talking about sidebands above the cutoff of the SSB TX filter and 
BELOW the suppressed carrier frequency of an USB signal).  On the CW 
bands, you'll see signals that are more than 50 dB down at +/- 300 Hz, 
and you see signals that are only 25 dB down at 1 kHz!  The former are 
mostly K3s (and a few Flex rigs with their new firmware).

> The mode can simply enhance or lessen the effects.

No, the distortions present in the equipment and the limitations of the 
rigs involved is what changes what you observe.

>   My demonstration is my desire to satisfy my personal curiosity -  I want to witness the issue or non-issue being described in the lab and I will be using two of the worst listed corporate violators based on forum Opinions ie Flex and Yaesu.

Your information on Flex is a bit old. Their 5000 series was a dog for 
trash, and the version of the 6500 that ARRL tested a year or two ago 
was pretty dirty, but the word I've heard is that firmware released soon 
after cleaned it up a lot. I've been trying to borrow on to measure to 
confirm that.

> Regarding your choice to upgrade, I am sure Elecraft appreciates your monetary and verbal support.  Remember to upgrade again once the bar is raised higher.

Yep. They just raised the bar with the newly designed synthesizer 
developed for their upgraded K3S, and made the synth board available as 
an upgrade for K3 owners. I upgraded my three K3s almost immediately.  
Tests by Rob Sherwood and ARRL Labs show quite significant improvement 
of phase noise on both RX and TX, as well as significantly reduced TX 
bandwidth.

> Perhaps TenTec will satisfy your need to upgrade with an Omni VII plus or an Orion III.

Those synth boards sell for about $240, and get me 90% of the way from a 
2007 rig to the brand new 2015 version. Compare that with the cost of 
going from an Orion I to an Orion II. With a company philosophy like 
that, it will take a lot to cause me to change horses. :)  AND -- 
Elecraft is a stable US company, whose two principals are EEs and active 
hams who read their own email reflector every day to keep in touch with 
their customers.

73, Jim K9YC