[Elecraft] K3: VHF/UHF transverters

[David Ferrington, M0XDF]

Hmmmm - I have an unbuilt XV144 and was not going to buy the K144XV because I thought I had read somewhere that the XV144 would be sufficiently better to warrant using the XV144 - but that would generally be portable or at an alternative address and via a 100W PA. Now wondering if the additional kit to carry (the XV144) makes it worth it.

The K144XV will give 8-10 Watts, the XV144 20-25 Watts - strikes me as I'd have to drive a PA with at least 10 and that would be pushing the K144XV, whereas I could reasonably get 15 - 20 from the XV144 and not get it too hot (a known problem?) and not over-drive them either.
73 de M0XDF
-- 
Mathematics is the language with which God has written the universe.
-Galileo Galilei, physicist and astronomer (1564-1642)

On 12 Feb 2010, at 23:29, Lyle Johnson wrote:

> Comments below
>> 1. Are the external (K144XV, 25 W) and internal (XV144, 10 W) 2m
>> transverters identical with respect to receiver specs? 
>> 
> The noise figure at the antenna jack on the internal transverter may be 
> slightly higher due to the PIN diode T/R switch.  The external 
> transverter has relay-based T/R switching.
>> 2. Is there a schematic on the web for the internal 2m transceiver, XV144?
>> 
> The schematic has not been posted yet.  However, I just compared the 
> receiver section of the K144XV the XV144 and, apart from the relay 
> versus PIN diode switch, they are essentially identical. I say 
> essentially because a component value may be slightly different due to 
> stray or parasitic PCB layout differences, but the circuit topology and 
> active devices are identical.
>> 3. If we want also to run an K432XV do we still have a choice between
>> running an internal or an external 2m transverters?
>> 
> Yes.  The internal 2m module has its own set of switched IF connectors 
> on the KXV3A (not KXV3) interface.  External Elecraft transverters hook 
> up to the external jacks.  If you use external 2m and 70cm Elecraft 
> transverters, they will both conenct tot he K3.
>> 4. IF the K3 has two receivers, can one listen on 2 m and the other on 70
>> cm?
>> 
> 
> I believe the answer is yes, *but* one will have to be interfaced using 
> the regular antenna connections.  The KXV3(A) only provides connection 
> to one receiver.  This is not compatible with the usual "daisy chain" 
> configuration of XV-series transverters.
>