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Show all reviews of the Stockcorner JC-4 automatic antenna tuner 1KW
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of the Stockcorner JC-4 automatic antenna tuner 1KW.
Aug 7, 2014 07:30
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A leap forward in remote couplers
Time owned: 0 to 3 months
Thanks to some ham friends I came in contact with Casper from Stockcorner. He is a fellow ham who likes development. His point of view: make ham equipment using high quality parts for the best possible price. After using the JC-4 coupler I can now tell the difference between most commercial tuners or copied Chinese junk and this remarkable high performance coupler.
Does the box needs to look appealing? No it doesn't. But open the sealed cover and you find a PCB board with the finest components on the market. Relays, coils, capacitors, all well up to the task. Soldering and finish is very HQ.
Presuming you have enough antenna length according the bands you want to work, the coupler allows you to run 1 KW SSB and 750 watts CW. It can cope with short antennas but the shorter the antenna on lower bands, Casper advises to reduce the power output. Also retuning has to be done with the linear amplifier in stand-by.
The tuning is very, very fast. Using smaller capacitor steps a very accurate tuning is provided. Besides, this model comes with two antenna outputs A and B. Both antennas can have up to 50 memories to recall tuned segments. But multiple setups are possible. A symmetrical dipole using antenna rods A and B result in a very good working all band doublet antenna, directly at both antenna outputs or with open feedline.
I'm using this to replace a dipole for 40 and 80 meters. I love the idea covering the complete band with good swr. Using 2 x 25 meters of wire fed with 600 Ohm open line to the tuner gives me a great antenna with nice performance on 160, 80, 60, 40 and 30 meters. (on higher bands I'm using a directional antenna).
The tuners supplied remote controller has a switch to select antenna A or B or switch both antennas to ground (also when powered off). A button lets you start the tuning process. It does not start without this button to make sure unwanted retuning can not happen while in qso.
Another nice feature: tune two different antennas (A and B) on the same frequency and you can compared them without the need to retune either one of them. This is really great and never seen on any other competitors model. Just flip the switch on the remote controller and you have a reading on the transceiver. Great to test antenna configurations and compare them on air with your qso partner.
Already tuned segments are recalled in milliseconds. New segments are tuned in just over 2 seconds. SWR is really 1:1 or 1,1:1 and not higher so your amplifier is happy.
As with all similar concepts, end fed wires or verticals need a decent RF ground to get good results. There's no magic involved here. If only a poor ground is to be provided, consider using the tuner for balanced antennas like dipole, doubled, G5RV.
Email response from Casper is great. He takes proud in his developments. There's also a 200 watt version and a 4 KW version available.
I've been using SGC smartuners, CG-models from China, MFJ remote tuners all using the same concept. So I've done quiet a bit of experimenting with different antenna solutions and brand tuners.
All I can say is this: once I've used the JC-4 I now know what a good coupler has to be. The JC-4 is a leap forward in remote coupling antennas to feedlines and transmitters.
I really can recommend this tuner. It's a class apart not being overpriced. I rate it 5 stars without a doubt.
Product is in production.
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