Call Search
     

New to Ham Radio?
My Profile

Community
Articles
Forums
News
Reviews
Friends Remembered
Strays
Survey Question

Operating
Contesting
DX Cluster Spots
Propagation

Resources
Calendar
Classifieds
Ham Exams
Ham Links
List Archives
News Articles
Product Reviews
QSL Managers

Site Info
eHam Help (FAQ)
Support the site
The eHam Team
Advertising Info
Vision Statement
About eHam.net

   Home   Help Search  
Pages: Prev 1 2 [3]   Go Down
  Print  
Author Topic: High End Transceivers and RX Design  (Read 2278 times)
K6AER
Member

Posts: 3525




Ignore
« Reply #30 on: November 24, 2009, 11:56:13 AM »

A transceiver is a sum of all its capabilities.



“It would be nice if someone like Sherwood would run receiver tests at very close signal spacings that simulate CW contesting.”

The problem with the above test is what would be your spacing?

Some CW operators want 200 Hz filtering while other that can separate tones in their head are happy with 500 Hz filtering.

Some radios are heavily dependent on DSP processing while others go the conventional route with multiple down conversions and expensive filters. Do we pay attention to phase distortion and in a crowded band condition how do we do definitive testing for this in the lab.

Many radios don’t have the same filtering available either due to IF bandwidth ratios or because of design architecture. The test would award best dynamic range as the ultimate goal while ignoring other shortcomings?

While building the ultimate CW transceiver would the radios ability to perform on SSB be a factor in overall consideration.

Case in point.

While using the K3, its operation on CW is quite impressive and silky smooth. The K3 has set the mark for other CW radios to meet.

Using the radio on SSB is at best a disappointment. The Audio EQ is not banded well. The RF output level indication on the S meter lacks dynamic range. The SSB transmit audio has very poor IMD and the speaker audio is wimpy at best and distorts badly when driving a 8 ohm speaker at one watt. It is obvious to any one who spends much time on SSB the radio was designed for CW first.  It is rare when I hear a good sounding K3.

Having a great receiver filtering system is only part of the package. The radio is not comfortable in SSB operation due to the other shortcomings.

Bottom line you must evaluate your radio choice for the operation you will need. If you need 160 to 3/4 meters, all mode, 100 watts, one button navigation your best choice will be the TS-2000. Should your specific need be 200 watts out you now have other limited choices.  I prefer a radio with a built in band scope over having to drag a monitor screen around. Now different choices have to be made.

To often hams forget that radios that are not well though out can be very fatiguing. This year we used 4, K3’s for field day. They did fine for CW but SSB was a disaster and visiting hams were lost with the K3’s unique ergonomics. We spent a large amount of time teaching special ergonomics.

All too often the ham radio community has been chasing the holy grail of adjacent channel dynamic range while ignoring other important areas.


A transceiver is a sum of all its capabilities.
Logged
WX7G
Member

Posts: 6146




Ignore
« Reply #31 on: November 24, 2009, 07:11:06 AM »

It would be nice if someone like Sherwood would run receiver tests at very close signal spacings that simulate CW contesting.

I've operated 160 meters for years and every receiver but the K3 would get crunched. My Icom 746Pro would get crunched although not as badly as the Kenwood 570. And the Yaesu FT-450 I used in the last ARRL 160 meter contest was very crunchable. Running a full size vertical over salt water away from the city I had a low noise level combined with terrific signal strengths from the guys in nearby states.
Logged
KC8QVO
Member

Posts: 62




Ignore
« Reply #32 on: November 28, 2009, 09:30:14 PM »

K6AER: All too often the ham radio community has been chasing the holy grail of adjacent channel dynamic range while ignoring other important areas.

A transceiver is a sum of all its capabilities.




True. Your description of the ergonomics with the K3 is one of the reasons I don't care for the K3. To me it is like a formula 1 car - the performance is fantastic but it isn't what you would want as a daily driver. The TT O2 fits in this category as well.

One thing I was thinking about with all this radio stuff is what is a bell and a whistle? You know, the saying "lots of bells and whistles" or "all the bells and whistles"? I think the FTdx-9000D and IC-7800 fit this category - mainly because of their displays, the "eye candy". However, do roofing filters, dual receivers, RF pre-selectors, and knobs count as bells and whistles? They are certainly more utilitarian in nature than is an LCD or similar display, though some may argue having waveform monitoring capability, among other functions, is a "utility". A roofing filter narrows the first IF passband for the rest of the receiver decreasing the affect of out-of-passband signals. Its like ABS on a car. It is such a useful feature that nearly all cars, maybe all now, have it.  

The reason I ask is if spectacular receivers could be made as general middle of the road (for the average ham) radios with good quality and feel, what would separate them from the "high end" radios? The short answer is "bells and whistles" - things to make it ultra luxury and fancy, above and beyond the "average" radio to make the price hike "worth it" to those fortunate enough to afford it. What really constitutes a "bell and whistle"?

Steve, KC8QVO
Logged
Pages: Prev 1 2 [3]   Go Up
  Print  
 
Jump to:  

Powered by MySQL Powered by PHP Powered by SMF 1.1.11 | SMF © 2006-2009, Simple Machines LLC Valid XHTML 1.0! Valid CSS!