[Elecraft] On VHF & UHF radios

Thu Sep 17 13:44:15 EDT 2015

There used to be a larger number of "serious weak signal VHF operators, but 
the serious VHF operators are all dying off with no young ones to replace 
them. I use three K3s and  three K2s in my VHF station. I have one Ten Tec 
OMNI V as well on 432. The big difference between a great HF vs VHF radio is 
that LO purity and reciprical mixing performance is paramount on VHF, while 
HF requires the close in dynamic range to be exemplary. I have yet to see a 
good multi mode or "do all" radio from any manufacturer. I have never used 
one in my station as a result. Strong signals on VHf can be a huge problem 
when giant antennas and high locations are in use. Stations 60 or 70 miles 
away can clobber you very easily. ERP levels can approach 150 KW.
    I have always been intrigued by the Sherwood numbers for the Kenwood 
TS-820S and TS-830 with YK88 filters. They don't look so bad in the listing, 
but they were awful on VHF in strong signal environments with high gain (20 
dBd) antennas. Local oscillator noise did not cut it.  The K3 with the new 
synthesizer is about 40 db or more better. I had the Kenwoods back in the 
90's and dumped them for K2s and Ten Tec radios. What a difference. The K3 
is icing on the cake. I started using them soon after they came out. They 
are great on VHF and not too shabby on 160 meters also. (heh heh) I don't 
think I can recall an overload problem with the Elecraft radios or the Ten 
Tec OMNI for that matter. The OMNI V used crystal oscillators in the 1st LO, 
so it was pretty clean. The new K3 synthesizer is awesome. It can handle a 0 
dBm signal next to a -135 dBm signal and live to tell about it!
    I have the 144 built in transverter in one of my K3's, but have not used 
it as it is too low power to drive my big amplifier. Someday I'll resolve 
that situation and it should work great. Of course VHF contesting is 
different in different parts of the country. I live in rural Maine about 250 
or 275 miles from New York City.  I am on the edge of the golden activity 
corridor. From my place, it is unwise to use multi mode Japanese rigs for 
serious contesting. Between the deafness and LO phase noise problems, you 
would have your hands full. Another ham 50 miles away could have a KW and 
large antenna that was line of sight or almost line of sight, and squash 
your receiver like a bug. Every  VHF band here has a good HF radio for the 
receiver. K3s, K2s, and one OMNI V from Ten Tec

Dave K1WHS


----- Original Message ----- 
From: "Bob McGraw - K4TAX" <rmcgraw at blomand.net>
To: <elecraft at mailman.qth.net>
Sent: Wednesday, September 16, 2015 12:03 PM
Subject: [Elecraft] On VHF & UHF radios


>I don't view there are many serious VHF and UHF operators today, i.e. 
>sufficient to warrant a high performance radio.  Most are repeater users. 
>Seems that a $39 radio model has been proven to be satisfactory to most.
>
> The SAT users do require some unique applications to cross band, split 
> frequency and address Doppler shift.  The Tropo users need big antennas 
> and lots of power and the EME group even more so.  Oh yes, the digital 
> modes make things less complex but still, big antennas, good receivers and 
> clean transmitters is still mandatory.
>
> I don't find the current breed of "do it all" radios to have outstanding 
> performance on VHF and UHF.
>
> 73
> Bob, K4TAX
> K3S s/n 10,163
>
> On 9/16/2015 6:35 AM, ae4pb at carolinaheli.com wrote:
>> I still believe it may be possible with the K3S, KRX3 and transceivers to 
>> do Full cross band duplex. I'll look more closely after my rig is built 
>> and on the air. Makes for an expensive stand alone UHF/VHF rig tho unless 
>> you want HF too. But then it's probably overkill just to work SATs. I'll 
>> bet with the correct transverter we could hear the mars rovers tho.
>>
>> Jerry Moore
>> AE4PB, K3S SN# ARRIVES TODAY!!!!!!!
>>
>>
>> -----Original Message-----
>> From: Andy McMullin [mailto:Andy at rickham.net]
>> Sent: Wednesday, September 16, 2015 7:22 AM
>> To: Jerry Moore
>> Cc: Jim Lowman; elecraft at mailman.qth.net
>> Subject: Re: [Elecraft] Elecraft SP3 External Speaker details
>>
>> I’d be interested in that spec too!
>>
>> Built-in soundcard for digital modes (with one USB connection for it and 
>> rig control) would be nice as well.
>>
>> Regards
>> Andy, G8TQH
>>
>>
>>> On 16 Sep 2015, at 12:06, Jerry Moore <jermo at carolinaheli.com> wrote:
>>>
>>> If they did a stand alone UHF/VHF I'd suggest it have dual receivers,
>>> cross band tx/rx capability and VFO tracking based on Doppler built in
>>> for SAT work.
>>>
>>>> [deletia]
>>>>
>>>> My one request to Eric, last year at his presentation at Pacificon,
>>>> was for a standalone, all-mode transceiver for 2m and above.
>>>> My rationale was that, since Elecraft sells transverters for 2m, 220
>>>> MHz and
>>>> 432 MHz, they already have the technology to make this possible.
>>>> It came down to the fact that there may not be a large enough market
>>>> for such a transceiver.  Makes sense.
>>>>
>>>> 73 de Jim - AD6CW
>>>>
>>
>>
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>
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