The TS-530/830 mod and upgrade thread

[N8YX]

Many years ago I had an early model TS-830S; this the result of doing some home improvement work for a ham buddy. The radio and a TS-520S were sold to finance the purchase of my first street bike, at which time I drifted away from radio...for a little while.

The late 80s saw me acquire a TS-820S, then an R-820. An AT-230 followed soon thereafter. Over the years, that tuner was in and out of the shack a number of times. I'd often thought of selling it, but the desire to obtain the rest of the x30 line lingered in the back of my mind.

Fast forward to today. There are several of the rigs plus peripherals and a good sized box of spare boards and parts in my project queue. In this thread, we're going to have some fun modifying and upgrading them.

The 530 and 830 share common DNA, as I remarked in a Q&A thread elsewhere in the forum. The chassis, power transformer, power supplies, Final Amplifier assembly, RF Board (with a couple component omissions in the 530 series), PLL Board and Counter Board are for the most part interchangeable between the series. What's mostly different are the IF and AF Boards. The '830 is a dual conversion receiver scheme which uses an RF speech processor, while the '530's is a single conversion arrangement with an AF speech processor. The 830's SSB TX bandwidth is set by a different filter than the one used for reception, while the '530 series uses the same filter for both - albeit switching in a "Narrow" RX filter at the demand of the operator.

We're going to take advantage of both methods to broaden up the transmit audio a bit, enabling the radios to be on par with today's offerings. We're also going to fix the various IF Board gotchas common to each, improve reliability of the radios in general and add a few cool features - some of which Kenwood already gave us a head-start on. This thread will be updated and edited as I go; feel free to add to it.

References and parts sources:

KE5FTF - hybrid parts (mostly used)

https://kd7dny.com/shop/

http://www.somis.org/830.html

http://www.k4eaa.com/parts.htm

[N8YX]

Tip #1: Better TX/RX filtering for the TS-530S

This one's pretty simple to do and offers improved TX audio quality as well as a more pleasant "Wide" SSB filter. The stock YK-88S (2.4KHz/6dB B/W) filter is swapped for a YK-88S-1 (2.7KHz/6dB B/W) unit. The filter can be scrounged from a number of rigs including the TS-830S, TS-940S and others which use an 8.83MHz IF.

As sourced, the rig included the YK-88C (500Hz/6dB B/W) CW filter. I added the YK-88SN (1.8KHz/6dB B/W) SSB filter and wired the Options jumper so that it's used as the CW-Wide filter (see photo):

530-filters.jpg

On-air tests with a station receiver using a Kenwood MC-50 were very gratifying. The '530 now sounds as nice as your typical EQ'ed ESSB rig, without exceeding permissible transmitted bandwidth.

Option: War Mode

Given the number of defunct sets and parts available in the marketplace, a dedicated individual could obtain a spare 530 IF Board and leave the stock SSB filter as-is, while fitting it with YK-88SN and YK-88CN (270Hz/6dB B/W) filters. If the set is to be pressed into contest use, the IF Boards can be swapped. This gives a little tighter, somewhat punchier SSB signal - which is desirable on a crowded band.

Other IF Board mods to follow.

[N8YX]

Tip 2#: Don't reinvent the wheel, Part 1

The 830 series rigs offer two IF Outputs on their rear panel. One is designed to be used with an SM-220/BS-8 panadapter and the other is a narrow-band pre-product detector signal, for use in looking at a received signal's characteristics. Unfortunately, the 530 doesn't offer these...

Or does it?

I started comparing the IF Board and circuitry to that of the TS-830S (for the wideband output) and to the TS-820S (for the narrowband output). Remember that the TS-530 is a close cousin to the TS-820 in terms of conversion scheme and IF frequency. The '820 also offers IF Outputs for scope and panadapter, so some component re-use might be possible.

Turns out that things are a lot simpler in execution. To wit, the '820's product detector interstage coupling transformer is where the narrowband IF Out signal is taken from. Doing a little digging, one finds that the same transformer is used on the 530's IF Board.

It gets better. Looking at the area in question, one finds that Kenwood provided traces in the PCB which facilitate installation of the required parts. Here's the bare board:

Bare-Board-1.jpg

Here's the board with the required components (a .001uF disc capacitor at "C31" and a two-pin header) added:

IF-Ou2-2.jpg

The header was obtained from a scrapped TS-930 Signal Board. Apparently, Taiko Denki produced the headers along with their mating plugs and the terminals used with them. Many rigs of the period use the connectors; Icom lists them in their Service Manuals as being TL-25 series. I'm planning to write T-D's headquarters and see if they're still available, or at least try to get a part number for the crimp terminals.

ETA:

Here's a picture of the terminal used in the plugs. They're 1.6mm wide across the triangle base.

KwdConnector2.jpg

Rear-panel connector addition and cable fabrication is covered later in the thread.

[W2NAP]

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[N8YX]

Tip 3#: Don't reinvent the wheel, Part 2

Also needed is a wideband IF output for a panadapter - namely, the BS-8. If one studies the '830's IF Board schematic and parts list around the area of the Noise Blanker roofing filter then compares everything to the 530's, it's clearly evident that Kenwood left us some breadcrumbs. Namely, lands with empty, pre-drilled holes.

At least one "retrofit" floating around the Internet has the signal tap taken before the 1st IF Amplifier (Q1) at the RIF terminal of J1. Implement it the way Kenwood intended - just add the missing parts.

The ceramic NB filter has to be bent carefully away from the holes in order for the required 2-pin header to fit into the space, but as you can see it's quite doable - and follows the '830's schematic exactly.

Pic shows new header and 10K, 1/4w resistor to ground, across the IF Out pin. Note the orientation - we're following Kenwood's connector keying practice:

IF-Out-1.jpg

The underside of the board, showing the new 47pF capacitor from the output side of L2 (ceramic filter input terminal) to the junction of the new header and 10k resistor. The two remaining empty holes had nothing in them to begin with:

IF-O1-PCB.jpg

Wiring of the rear-panel jacks (using Kenwood parts) to be covered next.

[N8YX]

Should be fixed. I noticed that hiccup earlier.

[N8YX]

Tip #4: Cosmetic improvements, Part 1

As shipped from Kenwood, the annunciator LEDs used above the VFO are all red. I wanted to give that area of the rig a little contrast, so I know at-a-glance what's going on with the various controls. This mod is applicable to all 530 and 830 models. (From left to right, the status LEDs indicate RF Attenuator On, Processor On, the rig's VFO is active and the Notch filter is on. This layout varies among models, and shown is that of a '530SP.)

LEDs used on the Readout board (immediately above the VFO assembly, and in front of the Counter module) are TLR-205. These are 1mmx5mm and are long since out of production...but they may be sourced from scrapped rigs (such as the FT-707's S Meter module) or the aftermarket. NTE 3161 (green) and 3162 (yellow) are direct replacements. I obtained the two yellow ones from one of my FT-980s, all of which are also getting the multicolor LED treatment - as their stock annunciators are yellow in color.

You'll need to remove the Counter module (several harnesses and four screws) to get at the Readout Board, then two screws remove it from the front panel. I used a green LED for the VFO indicator...and the OEM limiting resistor (R2, a 1.5k, 1/4w unit) made the LED a bit too dim for my tastes. Change this to around 1k while you have the board out.

The hardest part of the mod is getting the LEDs back into their front panel cutouts.

As far as the readout goes...nothing's faulty with your television. There's a gazillion wrong ways to add extra coverage to the x30 series rigs, and later on I'll cover the right way of doing it - via Counter module programming and use of the Aux band position.

Status-LEDs.jpg

[N8YX]

Wiring the IF Out

I wanted to re-use as much "Kenwood" as I could, given the availability of parts rigs and the components thereof. I also wanted to re-use the Kenwood style of construction, allowing for easy disassembly and module removal should servicing become necessary. An email to one of the parts sources listed in the first post got me a dual RCA plug from an '830, as well as a final compartment cover and the special transverter DIN jack (the addition of which will be detailed later in the thread).

As supplied, one of the leads was "just right" in length - but I had to scavenge another shielded cable plus terminals from part of a defunct '830 wiring harness, as the cable attached to the narrow-band output jack was about an inch too short. When constructing the new cable, I followed Kenwood's insulation convention for braid dressing. The installed jack assembly is shown here. OEM lead on the right; mine on the left:

RCA-Jacks.jpg

And the IF Board with the cables run to their headers. The cables were tie-wrapped into the harness at OEM points:

IF-Out-Wiring.jpg

[W2NAP]

nice work

[N8YX]

Tip #5: Improving transmit audio crispness

This one's taken from Rich Measures' (AG6K - SK) page, linked in the References section. The RF Bypass capacitor at the Mic Amp collector needs to be reduced, as the stock value also attenuates speech frequencies.

Applicable to both 530 and 830 series. Capacitor is identified as C53 in the 530 (adjacent to Q11) while it's C106 (adjacent to Q19) in the 830. Stock part is a .015uF mylar; I replaced it with a .0012uF of the same type and working voltage. I'll edit this section with a picture of the '830's circuit changes when I have one on the bench.

Mic-Amp-Changes.jpg