#34/35, Bring an old Kenwood ts-520 back to life part 1 & 2 - Page 1
Forum section: electronics / rf-microwave

author: Radio Tech
author_rank: Frequent Contributor
timestamp: March 07, 2016, 12:33:40 am
content: #34, Bring an old Kenwood ts-520 back to life part 1In this video we bring an old TS-530back to life with out a lot of parts change. This radio was very dirty and shows sign of moister damage. Will it still work after all this time?Part 2

author: retrolefty
author_rank: Super Contributor
timestamp: March 07, 2016, 01:26:16 am
content: These old Kenwood hybrids are quite collectible and even today command a pretty good resale value if in decent condition, considering their age. If the 6146Bs finals ever become totally unavailable then that may change but NOS stock still seems to be available.I picked up a TS-520S with CW filter for only $100 about four years ago, a great price. Still had original finals but found some NOS as spares.

author: Radio Tech
author_rank: Frequent Contributor
timestamp: March 07, 2016, 01:46:50 am
content: Quote from: retrolefty on March 07, 2016, 01:26:16 amI agree 100 %.They are excellent radios. Now I have 2I was really surprised at how little it took to get this one running. Thought it was going to be a hair puller when I first saw it. I like to find or have some paint that would match the covers and the bezel. Could really get this one looking great.At the moment I still have 12 NOS tubes.

author: AF6LJ
author_rank: Unknown
timestamp: March 07, 2016, 02:36:47 am
content: I have a TS-820 (no S model) When I received it it had a drifty VFO turns out Kenwood uses hot snot to secure the VFO coil windings.Well I didn't want to realign the VFO so I cleaned it with some acetone and replaced the hot snot. I was somewhat disappointed in the VFO design, from a mechanical standpoint it was okay. My issue is the total inductance used in the VFO tank coil was adjustable not a small fraction of that inductance like in a Heath SB series VFO. (the vacuum tube version)I have to open that VFO again it has developed the usual frequency jumping problem these things experience when they get this old. I'm going to try a little graphite on those bearings and on the contact that grounds the rotor.It is a fun radio to operate.

author: Radio Tech
author_rank: Frequent Contributor
timestamp: March 07, 2016, 02:47:59 am
content: Interesting Sue. Did the hot snot become conductive?I used the graphite a few times. Seems to work great and never had a return on one.I agree the SB series were a better design.Need to pull my older 520 down and do a little work on it. Change the caps and resistors then do an alignment. Also have a intermitted problem with the meter when in the tune position. It want work lol.When you go through you VFO you should record it

author: RobertoLG
author_rank: Frequent Contributor
timestamp: March 07, 2016, 02:51:27 am
content: man, it really looks cool with the blue leds, nice and cleanit has a cool look at inside too, the mechanic part, the chains, enjoyed to see it all

author: Radio Tech
author_rank: Frequent Contributor
timestamp: March 07, 2016, 03:12:45 am
content: Quote from: RobertoLG on March 07, 2016, 02:51:27 amThanks Roberto. You are the first to even mention the blue LED's I also think it gives it a "cool" look.These radios are built like a tank. Chains and all

author: RobertoLG
author_rank: Frequent Contributor
timestamp: March 07, 2016, 03:44:44 am
content: Quote from: Radio Tech on March 07, 2016, 03:12:45 amya, you see the quality in it, maybe I'm saying some BS here, but it would look really nice with a clear case and some ilumination inside with the right color, love these variable caps when they are clean and shiny

author: AF6LJ
author_rank: Unknown
timestamp: March 07, 2016, 01:42:41 pm
content: Quote from: Radio Tech on March 07, 2016, 02:47:59 amNo it was not conductive, it had pealed away from the coil leaving a half dozen turns loose on the form.QuoteI plan on it.I don't do videos, but do good documentation.Since I have a spare Heath VFO I can do a compare / contrast of the two units.The Kenwood VFO is better built than the Yaesu VFOs of the day such as the FT-200 or the FTDX-400 etc...

author: Radio Tech
author_rank: Frequent Contributor
timestamp: March 08, 2016, 10:02:40 am
content: Quote from: AF6LJ on March 07, 2016, 01:42:41 pmI seen your documentation. Great stuff!I bet you would do good videosBut no pressure.Looking forward to seeing you review.

author: AF6LJ
author_rank: Unknown
timestamp: March 09, 2016, 03:53:22 pm
content: When I get past the next two projects I have a couple that I may document. One is a Heath SB-110 six meter transceiver that is a work in progress. The second project is part 2 of my Heath SB-220 rehabilitation. Part one is in this thread...http://forums.qrz.com/index.php?threads/sb-220-find.372651/

author: Radio Tech
author_rank: Frequent Contributor
timestamp: March 09, 2016, 04:43:59 pm
content: Great, off to look at that now.

author: German_EE
author_rank: Super Contributor
timestamp: March 09, 2016, 10:03:39 pm
content: Good to see that TS-520 brought back to life but I'm going to go against the flow here and say no to those blue LEDs, I would prefer orange, yellow or warm white. Nothing personal, I just have a thing against blue LEDs everywhere. As for your rotatable platform, those are sold in some kitchen supply shops as something called a 'lazy susan', they're meant to be used for cakes and dishes that have to rotate when placed on the dining table. Price is a bit more than 1 USD thoughThe idea of a transparent case is an interesting one and I'm wondering if it would be possible. How hot do those finals get during use?

author: RobertoLG
author_rank: Frequent Contributor
timestamp: March 09, 2016, 10:46:43 pm
content: Quote from: German_EE on March 09, 2016, 10:03:39 pmwell, I'm just guessing here, but it got a fan at the backside, maybe not that hot to melt the plastic

author: AF6LJ
author_rank: Unknown
timestamp: March 09, 2016, 10:58:33 pm
content: I wouldn't do the plastic case for one thing that corner of the radio where the PA and driver reside gets hot even with a fan. Over time the plastic is going to yellow and become brittle.As for blue LEDs it is a matter of taste, I have a Kenwood R-599 receiver I replaced the internal lamps with white LEDs, they are coming out the very next time I need to work on that radio. They are too harsh to look at.I put current limiting resistors in my gear that uses lamps. The inrush current is the main killer of those bulbs and adding between 10 and 25 ohms (depending on the amount of current drawn) will extend their life more than ten times over.

author: RobertoLG
author_rank: Frequent Contributor
timestamp: March 09, 2016, 11:44:45 pm
content: Quote from: AF6LJ on March 09, 2016, 10:58:33 pmwhy don't you just change the color of the leds, like a warmer color, more like ambar or so? now talking about the clear case, maybe a not too fine inox mesh would do the trick, could you post some pics of your gear?

author: Radio Tech
author_rank: Frequent Contributor
timestamp: March 10, 2016, 01:15:37 am
content: Quote from: German_EE on March 09, 2016, 10:03:39 pmYep she is working like a charm now. I brought it on the house and have a fan dipole just laying on the roof. Works great.No problem with you taste in LED color. If I had orange they would had been my first choice. I like the "cool insert color" type of LED's over plain white. White really hurts my eyes.Paul (Mr Carlsons Lab) mentioned the lazy susan in the video. I think this one would hold a 200 pound cake with no problemNow about the clear case. Yes it would be nice as a display. But lets think for a moment.One problem as Sue suggest the plastic over time would discolor and become brittle over the PA area.So why would they use a metal case instead of a lighter heat resistant material?Simple, to keep unwanted RF from entering or exiting the rig. This could allow RF from an amplifier to get into the front end, power supply and other circuits of the radio. A plastic case would not stop this.I been to several ham fest over the years and watched dealers displaying amplifiers with clear cases on them. They had one that would key and un-key all day long to demonstrate how efficient the amp was. The whole time I am thinking just how much RF are these guys taking in.

author: AF6LJ
author_rank: Unknown
timestamp: March 10, 2016, 02:31:24 pm
content: Quote from: RobertoLG on March 09, 2016, 11:44:45 pmThis is a combination of a newer picturesand some I took last year...As for replacing the lamps with LEDs..When better looking LEDs come along I'll do it.For now I am good using the lamps and a limiting resistor.The IFR AM/FM 100S is old and crotchety; built in July of 1980 it has reached that point in time when it's reliability should be questioned. Riding around in the back of a service van has not done it any good.When it works, it works well...Still the best hundred dollars I have spent.

author: Radio Tech
author_rank: Frequent Contributor
timestamp: March 10, 2016, 04:33:44 pm
content: Very nice Sue.Love that equipment.I also see you have one of my favorite piece of test gear and was wondering who does the calibration?Attached below

author: AF6LJ
author_rank: Unknown
timestamp: March 10, 2016, 05:39:36 pm
content: It is self calibrating.

author: Len
author_rank: Frequent Contributor
timestamp: March 10, 2016, 07:15:56 pm
content: Quote from: AF6LJ on March 10, 2016, 05:39:36 pmAnd it can be used to calibrate any of the other equipment. Very useful!

author: Radio Tech
author_rank: Frequent Contributor
timestamp: March 10, 2016, 10:21:53 pm
content: Quote from: AF6LJ on March 10, 2016, 05:39:36 pm

author: RobertoLG
author_rank: Frequent Contributor
timestamp: March 10, 2016, 10:26:02 pm
content: Quote from: Radio Tech on March 10, 2016, 04:33:44 pmmultiple use tool

author: RobertoLG
author_rank: Frequent Contributor
timestamp: March 10, 2016, 10:30:18 pm
content: wow! nice stuff, love that radio on the bench, the one with the scopeand everything nice and shiny, beautiful

author: voltz
author_rank: Frequent Contributor
timestamp: March 11, 2016, 12:13:56 pm
content: Another good video Buddy. Nice work. And Sue, thats an impressive collection of gearWish i had an IFR, hard to find here in the UK.Hammers, we call them 'fine adjusters' in the workshop here. Or maybe 'universal programming tool'.

author: Radio Tech
author_rank: Frequent Contributor
timestamp: March 11, 2016, 01:26:36 pm
content: Quote from: voltz on March 11, 2016, 12:13:56 pmThanks.Sue sure has a nice collection there. Wish my work bench was that clean.

author: voltz
author_rank: Frequent Contributor
timestamp: March 12, 2016, 10:53:29 am
content: I do believe in keeping benches clear after a job is completed. Its good policy.Otherwise the mess grows over time. And the last thing I need is a scratch on a customers equipment because a nut or bolt got left on the surface. Never mind copper wire strands or solder shorting tracks on a pcb under test.. Nightmare. So, its a clean bench policy for me, after every job, i brush it down an quickly put hand tools away ready for the next job.Its nice, starting a job with a clean bench.Or, it could just be my slight case of OCD..

author: German_EE
author_rank: Super Contributor
timestamp: March 12, 2016, 07:19:57 pm
content: Keeping benches clear is always a good idea. I've got into the routine of tidying up the workshop every Friday afternoon including putting all the partially completed projects in their boxes and all the tools back in their right place. When working on equipment that could be scratched I use a rubber mat similar to this, screws drop to the bottom rather than scratch the case and stay in the holes rather than roll off. It's no good for working on boards though so they get removed and transferred to the anti-static workbench.

author: AF6LJ
author_rank: Unknown
timestamp: March 12, 2016, 08:12:33 pm
content: I always insist on having one small pile of Crap (a tool or two, some parts and hardware) on the bench.

author: RobertoLG
author_rank: Frequent Contributor
timestamp: March 13, 2016, 05:26:00 am
content: these Heatkits are simple looking, but at the same time very coolnice design

author: AF6LJ
author_rank: Unknown
timestamp: March 13, 2016, 02:25:52 pm
content: Quote from: RobertoLG on March 13, 2016, 05:26:00 amThey don't have the wiz-bang-features some radios of that era had.As for simple...The SB-401 (transmitter) is actually quite complex. The transmitter has 9 or so tubes in it and the receiver is dual conversion and is all solid state.