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Reviews Categories | Antenna Tuners | Stockcorner JC-4 automatic antenna tuner 1KW Help

Reviews Summary for Stockcorner JC-4 automatic antenna tuner 1KW
Stockcorner JC-4 automatic antenna tuner 1KW Reviews: 19 Average rating: 5.0/5 MSRP: $499 Euros
Description: Remote antenna tuner rated for 1KW pep. Two antennas. High
quality parts and high performance coupler.
Product is in production.
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KI6PU Rating: 5/5 Nov 15, 2015 12:41 Send this review to a friend
Excellent Remote Tuner  Time owned: 0 to 3 months
Several months ago I began searching for a remote tuner to help reduces the losses over 110 feet of coax and would also handle 600 watts. The JC-4s, newest version, arrived in about a week and was well packed for the trip. Its construction is of high quality to enhance efficiency.

The antenna is a G5RV type dipole fed with 600 ohm open wire transmission line. A 1:1 current balun is installed between the output terminals of the tuner and the open wire transmission line. One hundred and ten feet of coax is attached to the input of the current balun. So far I have not noticed any RF problems in the shack even though I run about 600 watts at times. The new manual for the JC-4s is a valuable source of information about using the tuner with various types of antennas. Customer service is excellent as I had several problems with coax connectors but after several suggestions my problem was resolved. The tuner is ground mounted and is covered with a plastic dish pan to protect it from the weather.

Using the JT-65 mode on 40 meters, the operating range at my station improved to over 10,000 miles opening up new DX possibilities. Operating HF with the JC-4s is now a real pleasure.

EC4KW Rating: 5/5 Aug 17, 2015 07:54 Send this review to a friend
Just Perfect  Time owned: 0 to 3 months
I was looking for a good remote tuner for my vertical long wire, i was reading about the CG-5000 for use it in QRO but some negative feedback made me change my needs til i just find the JC-4 for 1kw
Construction is very solid as you can see on the manufacturer web, good design and good performance for a reasonable price.
The package was shipped the same day after payment and i took about 5 days, very well packaged and comunication with Casper was clear and fast.
Installation was easy, and tunning is very fast, it can tune my 16.2mts wire on 160 mt band to 1:1 in 3 seconds.
Great ATU for a great value, worth the money.
SV1HFY Rating: 5/5 Mar 25, 2015 13:42 Send this review to a friend
Best tuner ever made  Time owned: more than 12 months
This is the best high quality antenna tuner I have ever used, it can even tune a nail! My only complain is the box should be of a better quality to withstand extreme weather conditions and sunlight exposure over time.

I am using it for a couple of years now with DDUtil and PowerSDR to auto tune my SDR and my vertical antenna using *only* a simple MAX232 RS232 to TTL converter from eBay for US$3-4 so the whole ant tune process is remotely controlled, fully automated and avoids dangerous and costly mistakes such as excessive power when tuning. Should also work with Flex radios. PowerSDR should also be calibrated correctly to reflect proper 9W output when tuning in any band and SWR protection shoule be disabled on TUN when Pwr < 10W.

Mini HOWTO use PowerSDR, DDUtil and a MAX232 RS232 to TTL converter to fully automate the antenna tune process with this tuner. The same setup can also be used to control quite a few other tuners.

You have to create two macros in DDUtil and use the RTS and CTS TTL signals of the serial to control the JC units. The RTS should be connected to the START of the tuner and the CTS to the KEY of the tuner.

Create two macros in DDUtil:

Tune On: DDRT1;DDLY100;ZZTU1;
Tune Off: ZZTU0;DDRT0;

With certain Icom tuners the DDLY100 should be changed to DDLY500. The delay should never be lower than 100ms.

Under "Ports" in DDUtil configure the serial port in "SerMacPort" where the MAX232 converter is attached. You should also change the value of CTS macro when Off to execute the "Tune Off" macro.

Also, under "Features" of DDUtil, check the "Tune Detect" and change ONLY the "Tune Off" to reflect the proper macro value of "Tune Off" but only the "Tune Off", the "Tune On" value should remain at the default value of 999.

NOTE: VERY IMPORTANT, YOU MUST NOT USE the TUN button of PowerSDR!!! USE ONLY THE "Tune On" macro button of DDUtil for everything to work correctly.
PA0FRI Rating: 5/5 Mar 20, 2015 07:10 Send this review to a friend
Great value for the money  Time owned: 0 to 3 months
Generally the tuner is able to match random rods and wire antennas, even if no antenna is connected. Not always with SWR = 1 but often with SWR < 2. It will be clear that with a short antenna the bulk of the energy is absorbed in the tuner itself. To protect the device one have to reduce the transmitter power significantly or use recommend length of antenna systems as stated in the documentation. In terms of price a JC-4 is an attractive alternative to similar but more expensive couplers from other manufacturers. It may be up to a difference of 50% in price: JC-4 1000W/PEP about EUR 500, SGC-235 500W/PEP about er EURO 1000. JC-4 has 11 coils and SGC-235 8 coils available to obtain resonance.

I confirm the review of OR5A.
TF3ARI Rating: 5/5 Jan 13, 2015 03:35 Send this review to a friend
He is now 7 Month old   Time owned: 6 to 12 months
just little follow up
I have now use the JC-4 for 7 month and still act like new . I run him 99% of the time with 1kw SSB from VL 1000 and Anan SDR radio
I have 2 antenna one on A and other on B input and I can switch remote from
A to B and roof is ground, mate of metal.
both antenna are 43 feet (13m) long ( one Hor and other Ver) and tuner is always 1.1.1 and my VL 1000 amp works well and run cold on this good SWR. I use this tuner on 80m to 10m ( also on 60m) alwas 1.1 SWR very unusual.He have also no problem with 160m 1.1 Swr and I run him 100w there and my antenna is short. Best tuner I have owns last 30 years.
CX2AL Rating: 5/5 Dec 4, 2014 16:19 Send this review to a friend
Magic box  Time owned: 0 to 3 months
I have used the JC-4 for almost three months now.
My antenna is composed of a 40m horizontal long wire about 30m above ground and a vertical 20m counterpoise.Connected to one end of the LW, the JC-4 will tune it to any ham band from 160 to 10m in a matter of seconds to very low SWR, most of the time 1:1.1.
I have owned in the past MFJ, LDG and SGC tuners, the JC-4 outclasses all of them.
Keep up the great work Casper!
N8IL Rating: 5/5 Dec 4, 2014 05:25 Send this review to a friend
Fast & Easy!  Time owned: 0 to 3 months
I've had the tuner for two days, and will do a follow-up review after a few months.

I run a K3 with a Yaesu FL-7000 amplifier that makes up to 700W CW on 40M with peaks of 800W PEP on SSB.

I had a popular brand name desktop tuner which worked OK, but I was getting RF in the house. I decided to try a remote tuner. I came across the reviews on this page and decided to give the JC-4 a try.

I ordered the tuner (14 days shipping from EU) and ran a control wire and soldered the connector to the antenna-end while waiting. The documentation is available on the web site. One thing that is unclear is that the small control box is included with the tuner.

I have an end-fed Zepp that shows 5:1 on 160M and 3:1 on 80M. My first attempt at tuning with the JC-4 was surprising. It took about three seconds. I really thought it was too good to be true. (The old tuner took up to 30 seconds.) After using it for several hours at varied power levels across all bands, I can say I would enthusiastically recommend it to those of you that need a remote tuner and are not running legal-limit power (It's limited to 1,000 watts, and they do have another model for that.)

The quality of construction and parts is outstanding. It's also nice to have the relay noise outside the shack. :)

The I can't complain about the mic connector as mentioned on another review. You just have to seal it to your own liking. I do the same thing to the RF connectors, so it's really not a big deal.

Good hamming!!!

SV1JCZ Rating: 5/5 Aug 30, 2014 08:56 Send this review to a friend
Time owned: 0 to 3 months
The Nice Tuner JC-3 / RAN3 (200watt pep SSB) & JC-4 / RAN5 (1000Watt pep SSB) are construct in Athens Greece by SV1NL

I have the Ran3 for Portable use and the Ran5 in the second QTH with a 18m Spiderbeam Pole as Vertical Antenna.

Here the Manual in Greek Languish:

73 Danny
OR5A Rating: 5/5 Aug 7, 2014 07:30 Send this review to a friend
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.
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