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Reviews For: The Heathkit Shop AC-4R Drake Power Supply Upgrade

Category: Power Supplies

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Review Summary For : The Heathkit Shop AC-4R Drake Power Supply Upgrade
Reviews: 13MSRP: 65
High quality PC board and new parts to upgrade the Drake AC-4 power supply. Provides all new capacitors plus higher rated diodes and resistors. Fits inside of the AC-4 case.
Product is in production
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# last 180 days Avg. Rating last 180 days Total reviews Avg. overall rating
W3CRR Rating: 2012-03-15
For AC-3 owners, too! Time Owned: 6 to 12 months.
On his website, Mike states that his AC-4R Drake power supply upgrade kit does not come with instructions for installing it in an AC-3. If you own one of the older Drake power supplies and are afraid (as I was) of ordering the kit because of this -- relax!

Upgrading an AC-3 with this excellent product is downright intuitive. The kit's well marked (and first quality) PCB makes it easy to match the old and new wiring. The only complication -- if you can even call it that -- is the drilling of a couple of mounting holes for the new circuit board and maybe one for an added terminal strip. Once you're done -- and it will not take anywhere near as long as you fear -- you'll have a "new" Drake power supply you can rely upon for many years. In short, if you haven't upgraded your AC-3 yet - do it now! It's easier than you think. (In fact, fitting an AC-4, even with Mike's excellent step-by-step instructions, is more complex).
WB8YQJ Rating: 2011-02-11
Essential Product Time Owned: 0 to 3 months.
I had five AC4 power supplies, knowing that with age I would need spares. I upgraded two units this time and after having a look inside it occurs to me that ALL AC4's by now need this upgrade. It is cheap, less than one repair along the way of an AC4 that loses a cap and/or some diodes, and effectively makes the upgraded AC4 "NEW" assuming the transformer has not been compromised in it's earlier days of operation. The instructions were "marginal" for me. They are meant to be simple and intuitive for those who understand the relationship of the parts to the schematic but that was not me. If the color wire called for is not there for me, I have to punt (ask for help). The AC4's will be constructed with some differences. At one point you are instructed to "remove a terminal post" which I happily cut out, but the idea was just to unscrew it. No mention of diodes on that strip, they are there and I correctly removed them. The instructions are in black and white and referring to colored wires. The yellow wires were too thick to go into the PCB, after stripping I removed 3-5 strands of the wire. The other colored wire fits. On both my units the lower transformer bolts ended right at the bolt - no room for a stand off. Improvise here. ;-) When you are finished you will feel better (and for good reason) about using your T4X, this is the way Drake would have designed it back in the day if these high quality parts were available then. No hum - good power - best possible result.
W0EAJ Rating: 2011-01-24
questions Time Owned: 0 to 3 months.
The quality is first-rate, but the instructions leave a bit to be desired. Not all AC-4's are the same I guess, because the instructions did NOT match this AC-4 - somewhat ambigiuous concerning descriptions ("center terminal" and "2nd. from left"), when dealing with a strip that has 4 posts (okay, which one do YOU consider center?).

A few more pictures would be helpful I suppose - No, I'm no novice - been doing this sort of thing for a living, for YEARS.
N6TLU Rating: 2010-05-29
Highly Professional Kit, Recommended by D-Lab Time Owned: 0 to 3 months.
I am an electronics tech by profession. Maintain my own rigs, plus repair others and make tube amplifiers. I try to be a perfectionist in everything I do. I have a Drake B-Line, which I love, but hated the old yellow leaking caps in the AC-3. I decided to buy the AC-4R kit. I went cheap and spent the $55.00 for the basic, No instruction or wire version. I received the full kit with a note from the owner! I was very impressed. Great service. Fast US Priority mail shipping. I made a few changes for mounting the PCB and wiring. Too much to cover here. However, I will be shooting a YouTube with details. This Power supply upgrade is brilliant! I wish their company the best. Good to see someone making a difference at a reasonable price. 5 stars!
K5UI Rating: 2009-12-31
Definately Worth The Money Time Owned: 0 to 3 months.
Every Drake AC-4 owner should know about this upgrade kit. I ordered mine after turning on my T-4XC one morning and hearing the all-too-familiar motorboat sound of an aging capacitor. I recap a lot of older tube-type radios and expected to do the same with the power supply. On closer inspection it became apparent that to do so in the limited space of the AC-4 power supply would be an exercise in frustration and would create a fair amount of (potentially expensive) mis-wiring risk. The upgrade kit solved both issues at very reasonable cost.

As noted by others, the instructions were clear and generally quite detailed. Total time for me was a leasurely and enjoyable 4 hours.

A couple of quick items worth noting if you are ready to build yours: 1) You may not be able to install all the standoffs until the old caps are out of the way. No problem waiting on this step until the PCB is ready to mount. 2) When installing new wiring on the bias pot, it will be easier to reverse the first 2 steps - i.e., connect the far terminal first, then the center terminal. 3) For me it was easier to jumper over the brown wire and the blue wire from the fuse holder for the final test. If you want to jumper this over at the plug end, the correct jack spots are the second and third from the left on the top row with the 6 parallel slots on top.

As advertized and works great.
K3VYY Rating: 2009-10-10
GREAT Product! Time Owned: 0 to 3 months.
Bought a TR4C/AC4 from an estate of a club member. Someone had 'repaired" the AC4 and it had set around for several years. When I got it some diodes in the HV section were bad, so just decided to get one of Mike's AC4 upgrade boards! I was in no hurry, but finally finished assembling and installing the board. The design is great, easy instructions to follow. I am EXTREMELY pleased. Now I'm going to have to upgrade my two other AC4 supplies!
W1CC Rating: 2009-01-26
Simply a Must for Any DRAKE AC-4 PS Time Owned: 0 to 3 months.
I ordered the AC-4R on Sunday and it arrived on Thursday and after 4 hours of work, my T-4XC now sounds better than ever. Great product and service. Order this upgrade for your peace of mind alone.
K9JP Rating: 2009-01-05
Outstanding Service Time Owned: 0 to 3 months.
Just wanted to say all you get from Mike at The Heathkit Shop is
OUTSTANDING SERVICE! The up-date kit for the Drake AC-4 power supply is EXCELLENT! Easy to build and install, directions are perfect. Thanks Very Much! de Jeff - K9JP
KI6NQT Rating: 2008-10-12
No worries here Time Owned: 6 to 12 months.
This kit is well designed and fits well.
Works with the AC-3 and AC-4.
HB9OBZ Rating: 2008-01-11
DRAKE AC-4R Power Supply Upgrade Kit Time Owned: 0 to 3 months.
I have succesfully built one of the two kits you sent to me and have installed it into one of my HUMMING AC-4's (high serial No. with factory built switch 120-240V) which had one blown off cap and one fried diode. The kit is very simple and straightforward to build. The manual is very exhaustive and clear to follow as the good old Heathkits were !
I also appreciate the high quality of the PCB and components and the honest price of the kit.
After readjusting the BIAS I could operate my TR-4C, with the correct DC voltages 656V, 272V + neg. bias, WITHOUT ANY HUM !!!!!!
Now I will build the second kit and install it in one older AC-4 which powers my T4X-C.
Alex, HB9DTA