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Reviews Categories | Specialized Amateur Communication Products | K4DPK VFO STABILIZER Help

Reviews Summary for K4DPK VFO STABILIZER
K4DPK VFO STABILIZER Reviews: 14 Average rating: 5.0/5 MSRP: $$70.00 Shipped
Description: Greatly reduces drift in conventional VFOs and PTOs. This device has been installed and proven effective in a great many older rigs.
Product is in production.
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K4SUE Rating: 5/5 Dec 7, 2017 16:23 Send this review to a friend
Applied to the Drake R4C  Time owned: 0 to 3 months
Having experienced the dramatic improvement in VFO stability the K4DPK stabilizer made to my Yaesu FT301D I decided to give it a try on my R4C project radio.
Initial frequency stability runs on the PTO in the radio led me to believe that it was too unstable to be tamed. That proved to be true - 240 hz drift in the first 30 minutes, another 170 hz in the next 30, and the PTO never did settle down.
I installed another PTO which drifted less that 100 hz the first 30 minutes and the stabilizer works like a charm. Results are less tha 10 hz drift in first hour and less than 3 hz per hour from there to infinity.
I can't say enough for the product and the support Phil provides.
Definitely my choice for any other boat anchor projects.
VE3IPW Rating: 5/5 Oct 2, 2017 18:35 Send this review to a friend
Excellent product.  Time owned: 0 to 3 months
I have to agree with GMOHKS that the VFO stabilizer from K4DPK does what it is designed for.
It was a bit of a challenge to install in the Kenwood TS-830S. Patience required. You have to disassemble the VFO to get at the solder points on the tiny PCB. I choose to connect to the component side of the PCB. On my first go, I did not notice a single strand of wire which caused a ground. The result was that the stabilizer did not work correctly (too much drift). With some encouragement from Phil, K4DPK, I revisited my installation and found the pesky little strand and fixed it.
On power up, the 830S drifts not more than 200Hz in the first 45 minutes, after the warm up it is rock steady. 8 hours later it is still on the exact same frequency. Truly amazing. This stability far exceeds the Kenwood specs.
I connected the stabilizer power leads as suggested by GMOHKS. I hot glued the stabilizer in a vertical manner in the optional filter spot.
This is a great product and it exceeds my expectations and also helps resurrects an iconic transceiver.
Regards, VE3IPW
GM0HKS Rating: 5/5 Feb 11, 2017 07:16 Send this review to a friend
TS830s vs K4DPK Stabilizer  Time owned: 6 to 12 months
Phil very kindly shipped my circuit board from the States to Bonnie Scotland in quick time. Being a great enthusiast of the Kenwood hybrid gear, I was keen to "tame" the VFO in my TS830s and I've not been disappointed. The installation went smoothly and I sat my "old lady" on a 7 Mhz broadcast station for some five hours. Didn't budge. For information to other TS830s owners; when connecting the red and black power cord to the VFO board I did the following; There is a useful 12v dc source on the Audio board, (its on the underside of the 830s). I tack soldered the red positive volts lead wire on to the 12vdc regulated wire wrap terminal post on the right hand side of the AF board. It has 3 wires attached to it. White yellow, White red, and Yellow. It is just to the left of capacitor C81. The negative black lead end was formed in to a loop at the end and I applied some solder to it. I then screwed it underneath a chassis screw and washeer holding one of the boards down. Job done. Using some hot melt glue, I attached the PCB to the lower chassis casing. Where its positioned, I can see the green LED flickering through the vent grills on the back topside of the 830 casing. Phil's after sales assistance was superb and I move forward as a "very happy camper". Great product, great price and easy to install. If you have a TS830s with a bit of a "mustang" VFO inside, get one of these devices. It sure will tame it. 73 and good luck Will / GM0HKS
K5APL Rating: 5/5 Jan 3, 2016 20:15 Send this review to a friend
It Works Great  Time owned: 0 to 3 months
I added the K4DPK VFO Stabilizer to my TenTec Triton VFO and am very pleased with it. While the VFO/PTO was apart for a rebuild, I added the stabilizer circuitry to compare a rebuilt PTO/VFO to the stabilized version. From a cold start, the original VFO drifted down approximately 400 cps (Hz) and then stayed pretty stable unless the temp in the shack changed a lot (my shack is a storeroom w/o climate control). Throughout the day I would need to touch up the
tuning slightly. After installing the Stabilizer, the tuning stays put on frequency. I didn't measure frequency drift, but the net I was listening to on 20M in the morning was on frequency in the afternoon, without changing the tuning knob. I found a couple of things that helped my installation. First, I notched the VFO compartment and bracket to replace the VFO cover and the radio's bottom cover without crimping the coax to the Stabilizer board. And, I used "Shoe Goo" to "glue" the coax cables so they would not move or vibrate, and also I "glued" the varactor and it wiring inside the VFO compartment. I can now rap the radio, and shake it and the frequency stays stable. Your VFO situation might not need the "Shoe
Goo" to stabilize wiring, etc. Now I can listen to a net, or a QSO, without having to touch up the tuning as time goes on. I am very happy that it performs as advertised on my 35+ year old radio.
K4SUE Rating: 5/5 Jan 2, 2016 13:35 Send this review to a friend
Revised review  Time owned: 3 to 6 months
I recently acquired a frequency counter and can now quantify the effectiveness of Phil's VFO stabilizer.
With the stabilizer off, the 301D VFO drifts -240 hz from turn on to 1 hr. After that it drifts an additional -170 hz the next hour, -90 hz the third hour, before settling down to <10hz after 5 hours.
With the stabilizer on, the drift from turn on to 1 hour later is -30 hz, followed by <10 hz the next hour and beyond.
This is an excellent product.
KJ7CY Rating: 5/5 Dec 15, 2015 09:24 Send this review to a friend
Great Product  Time owned: 0 to 3 months
I bought the K4DPK VFO Stabilizer for my Ten Tec Corsair II, this is a great upgrade to a fine transceiver. The VFO had been rebuilt a few years ago, but still drifted a lot. After installation of the stabilizer, there is no drift at all for two to three hours. This is a huge improvement compared to before. It used to drift 300 hertz in the first 15 minutes, I would let the radio warm up for an hour before using it. I was always fiddling with the VFO, now I can use it as soon as I turn the radio on. Installation is so easy, clear instructions are included. If you can solder, you can install this circuit board. I used double back sided tape and installed it on the inside wall of the chassis. There is only four wires to solder to the bottom of the VFO, as well as a Varactor Network (included and already soldered), and a positive and ground wire. Phil was very helpful in answering any questions I had. I would definitely buy this product again.
K7AMS Rating: 5/5 Feb 12, 2015 23:14 Send this review to a friend
Fantastic device for old radios  Time owned: 0 to 3 months
I just installed the K4DPK VFO Stabilizer in a Drake R-4C receiver. It is basically a three wire install. I did have to take the cover off the PTO. Now the receiver will lock any frequency for hours or until you move the dial.
Phil, K4DPK, builds the stabilizer himself and is quickly available to answer questions if you need help to figure out the installation.
I would not hesitate to the recommend this device to a friend or to purchase another one to stop a radio from drifting.
W2SDR Rating: 5/5 Sep 13, 2014 11:30 Send this review to a friend
Good unit and well constructed with clear instructions   Time owned: 3 to 6 months
This is an updated review.
The unit has been fine and had good customer support
KY5U Rating: 5/5 Sep 12, 2014 19:32 Send this review to a friend
Great Great  Time owned: 0 to 3 months
Bought one for a Swan 350, and it was idiot-proof to install. Worked great and exceeded my expectations.
N2PD Rating: 5/5 Apr 23, 2014 18:20 Send this review to a friend
Works as described  Time owned: 0 to 3 months
I received the stabilizer and installed it in my Kenwood TS-830s and initially it did not work. Phil went out of his way to help me get it right. Turns out there was nothing wrong with the unit. I sent it back to Phil and he checked it out and sent it back with a lot of helpful installation tips. Got it working on the second try and never looked back. Vfo is now rock stable. I no longer need to use the VFO-230 I have which is digital. Rig stays right where you put it. Much thanks to Phil for a great product and wonderful support. Definitely worth the bucks.
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