[Elecraft] Digital modes on 144MHz only

[Jim Brown]

In today's world, a mast-mounted preamp is a waste of effort for the 
vast majority of hams because circuit noise in the receiver is rarely 
the limitation on what we hear. Rather it's all the trash from the 
electronics in our homes and homes of our neighbors, in addition to 
power line noise. I've recently been working 6M grid expeditions to VERY 
quiet places, and the ops say that they have to run high power to get 
over the local noise of the stations who want to work them.  That's why 
I bought the KPA1500 that will show up next week. :)

Most of the time, my QTH is pretty quiet, and although I'm running 500W 
to 4-el at 120 ft fed with 7/8 hard line, I nearly always give a signal 
report that's 10-15dB better than I receive. Today I worked a station 
double-hop E-skip who I gave +1 and he gave me -24.

When it's quiet, it's because I worked to make it that way. When it's 
not, it's when some new source fires up.  One of the things I'd be 
concerned about with the internally mounted transverter is frequency 
stability due to the additional internally generated heat.

I don't know how they're building them now, but the XV144 and XV220 I 
bought used about 15 years ago have serious bonding issues, and they can 
be a bit unstable. One of the most serious design faults is the that BNC 
I/O connectors are insulated from the shielding enclosure!  Hello!  
Clearly the designer did the wrong thing to fix whatever instability was 
caused by other errors.

73, Jim K9YC



73, Jim K9YC

On 7/4/2019 3:11 PM, Bob McGraw K4TAX wrote:
> Make sure you balance the station receive performance with that of the 
> 1 KW amp.   Power is easy to generate.   Low noise receive performance 
> is a challenge.   Start with a mast mounted low noise preamp, then low 
> loss feedline such as 7/8" hard-line, and such. Remember, loss in the 
> feedline adds to receiver noise.
>
> I encounter many stations that have great signals but seemingly can't 
> hear other stations calling them.  I call them alligators.......all 
> mouth, no ears.