The goal was to enable an already feature-rich radio with SDR receive capabilities near that of a Flex Radio or K3 with LP Pan. There has been much debate within the TS-480 Yahoo forum surrounding which IF to tap, 10Mhz vs 70Mhz. (Ask me why I no longer participate in said forums…)

The 1st IF (70Mhz) provides much more spectrum to feed into PowerSDR although required specialized hardware to even tune the 70Mhz IF. If you already have made a capital expense into a Perseus or like radio this wouldn’t be an issue. The 2nd IF is downstream from the roofing filter which limits width to roughly 20khz. I know what some of you are thinking.. “This is useless, you don’t know what you’re doing. Go die in a car fire!” I beg to differ. (Ask me about forums again…)

If you need 96k or 192k of SDR bandwidth, buy a Flex 3000 or 5000 like I ultimately did. They rock! But if you want to have some fun with what you already have, read on.

Here’s what you’ll need:

WARNING!!! – I am not responsible if you wreck your radio. You assume full responsibility for your actions. This WILL void your warrantee. You have been warned.
Now drink because I’m writing this based on my memory of doing this project almost a year ago.

When you open up your radio (the side with the lit logo), you will be faced with the logic board. This board is where the filter board and voice keyer plugs in. Disconnect the grey coax jumpers (these are the IF lines), remove the grey cover where the voice keyer goes. Also remove the filter board.

Remove the remaining screws holding the board in place and remove the board from the chassis. Turn it upside down. We will be working on the underside. What was once on the right will now be on the left (for the spatially challenged).

Read this part carefully.
Cut the teflon coax in half, solder one end of the cut RG-174 to the input of the buffer, the other to the solder side of the board where the 2nd IF coax socket is located (circled in RED). Center conductor to the small solder point (top), shield to the larger (bottom).

We now need to provide power to the Z10000 buffer. I accomplished this by piggy backing power from the PWR1 (HX model) side of the radio. The reason for doing this is to provide power to the buffer even if it is in RX Only mode (HX model) with one leg of power connected.

Carefully turn over the radio and remove the panels to expose the RF deck. Locate the radio’s power leads (large red and black wires). Solder some power wire (light gauge) to the power input of the buffer and route it through the side of the chassis to reach the other (top) side of the radio. Solder the buffer power leads to the power leads of the radio. See photos.

Power up the rig. If it works, you did it right! Congrats on not destroying your radio!

Turn off the TS480 and connect the Softrock antenna input to the mini-sma connector you’ve just installed in the 480. Power the beast back on.

Tune your Softrock receiver to 10.550 which I believe is the 2nd IF frequency of the TS-480 (going on memory of a year ago). The audio output should be wide frequency audio with very high pitched sound and should change as you roll the VFO knob.

Download and Install PowerSDR-IF from WU2X. Follow through the steps he’s indicated in the “Getting Started” section. With some success, you should see similar results as below.

SDR Bandwidth – Going back to the 1st vs 2nd IF debate, I’ve had excellent results with the approximate 20khz bandwidth provided by the 2nd IF. With applications like CW Skimmer, I was able to “hear” CW QSO’s 10khz above and below my selected center frequency. Eg, Tuning to 7.010Mhz would provide decoding of 7.000 to 7.020. The waterfall in Skimmer was much clearer with more successful decoding by utilizing IF tuning over typical 3khz audio output. With this setup I was able to dramatically increase my CW QSO rate in a contest only weeks after I completed this project.

Buffer Gain – I stated that I “winged it” when I selected 4db of gain on the buffer when I ordered it. This was based on documentation interfacing the Kenwood TS-2000 to the LPPan. I felt they may be similar.

Panadapter Anomalies – A noticeable null in signal is present in SSB and CW modes on the panadapter at the center frequency. This is not audibly present. A workaround I employed was tuning my IF receive frequency down by 5khz (10.500) on the Softrock and adding offset to PowerSDR to line everything back up. This may be caused by the Softrock. Need further testing to prove out.

Mirrored Waveforms – You may see mirrored waveforms surrounding the center frequency. I believe this to be caused by delay in phase between the I and Q outputs of the Softrock. This should be resolved by utilizing a higher quality IF receiver such as an LP Pan or like hardware.

My search ended while browsing some eBay auctions and was instantly introduced to the Chinese OEM-type switching supplies used in various devices and appliances. The prices were very reasonable, 30A supplies for approximately $50. How good could they really be?

I remembered hearing something early on about switching power supplies causing interference in the shack, or generating hash so loud, it would cover-up the reception of weak DX stations. I immediately started my search on eHam to see if anyone else had attempted using similar supplies and expected to hear the usual horrific war stories. I was surprised to hear something positive on the subject with many hams having gone the same direction.

Here’s a link to one of such discussion threads:
http://www.eham.net/ehamforum/smf/index.php?topic=71829.15

With that in mind I found an eBay auction for 2 units and purchased both.

Upon wiring up one of the supplies with Anderson power-poles leads for output DC and the stripped back end of an extra computer power cord for the input AC, I was ready to unleash my abuse. Below you will see my findings tested with a power meter used for troubleshooting electric RC airplanes. The meter displays voltage, current draw, watts and amp hours and has been a very sought after tool in my shack. I highly recommend picking one up.

The first photo shows current draw on one supply leg of a 200w Kenwood TS-480HX at 100% duty-cycle, full output. Current draw measured was 19.5A.
The second photo captures nominal output voltage of 13.24V at minimal load. 1.2A was measured with the radio on and idle. This was the maximum voltage I could get out of this supply.
The third photo indicates the voltage drop with a 19.5A load. Output only dropped .25V.

OK so it looks like the supply will do 20A fairly easy. But will it output it’s rated 29A? I was able to draw the radio’s maximum current draw from just one supply. This is probably a bad idea but it does seem to do it.

In addition to testing the supply on the bench with an oscilloscope (which output a clean DC trace), I also tested it with the 480HX at full output on CW. Not a hint of RF hash was detected.

I’m only a couple days on the new supplies and I’m very happy with my decision to go this route. The RF hash issues with these types of supplies seems to be a thing of the past. Long gone as the technology has gotten better. However I did notice a voltage output difference between the two units I bought. One of them outputs 14.8V max and the other 13.6V. This doesn’t seem to be all that critical for this application, but could indicate a QC issue during manufacturing. I don’t know who made mine, since I can’t read Chinese, but similar supplies can be found on-line under the name Mega-Watt or other makes with the similar red lettering in the upper left-hand corner of the printed label.

One of the other things to keep in mind is that the terminals are exposed, a concern especially for the AC input terminals. I plan to mount mine in a 2U rack enclosure with Power-pole panel mounts, an AC switch and volt meter. That should address the electrocution any nosy cats who may exploring the shack.

Until next time, 73!
de N3QO
dit dit

How to resolve this? Reduce your coax run length and quantity by using antenna switches.

I reviewed a number of designs online and ended up designing my own, 2 position antenna switch which injects 12VDC onto the coax, so we didn’t require additional long lengths of control wire which could end up resonating RF.
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For the next 3 weeks part of my station would be turned into an assembly line, etching circuit boards, fabricating cases, etc.

A week before the contest, Eric and I put the switches through their paces by dumping 2.5kW at 100% duty cycle for about 10-20 seconds. This would help us assure that they would hold up to the contest pace.

I ended up building five switches, 2 rated at 10kW and 3 rated at 5kW. I’m happy to report success with the design with no smoke emissions. One thing we did find was a high SWR at 15m and above, which I believe I have a fix, that needs future testing.

Back in September/October 2010 timeframe, I was looking to start working satellites after making contact with the International Space Station (ISS) from the car. I would end up buying a Yaesu 5400B az/el rotor, Tracking system, M2 2m circular polarized antenna and sell my Icom 746 for a Yaesu FT-847. I was set, or so I thought.

I would go on to burn out the motor twice on the 5400B rotor, with the already $1200 investment I had in the project, I would need to add an additional $900 on a 440 circular polarized antenna, and pre-amps for both. Needless to say what’s left was the 847, 2m antenna and tracking system, which most likely would go on ebay.

Recently I started getting back into digital modes, RTTY, PSK and CW and found that the 847 was quite sloppy on the receive side when trying to get selective on the station you are trying to work. With some research, I found the 847 itself had a 2.7k receive filter which was used on both SSB and CW. Quite wide for work below 170hz wide and nearby stations would end up desensing the receive causing the intended station to merely disappear.

What to do? Add filters of course! I opted to go with a different radio instead, and I’ll tell you why.

I’ve read a number of reviews about filter options for the radio including this one, which gave me hope of increasing the receive performance of the 847, although there is a fairly major flaw with the way Yaesu designed this rig. The filter that is already in place is a 2.7k and it is on full time. If I were to replace that with a 2.1 or 1.8, that would be fine for SSB phone work. Same thing with CW, drop a 250hz INRAD in the second slot and CW performance would most likely be spectacular. But what about PSK and RTTY? Both as SSB modes. Unlike the 746, there is no menu setting that I can change that would use a CW filter for SSB digital modes.

If I were to then replace the 2.7k filter with a 250hz filter for use on RTTY or PSK, the radio would then be useless for SSB Phone, because that filter would be on full time. Not exactly flexible in that respect.

So the thought was to replace this rig with a Kenwood TS-480HX and have it serve in the shack on a temporary basis, until I acquire a Flex 3000. The 480 would then go in the mobile in place of the 706 which came into the shack on the YL’s desk during the last PA QSO party.
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Any New Year’s resolutions? At first I didn’t think I had but I guess mine would be the following:

-Actually learn code (CW) besides, CQ DE N3QO, 5NN and TU. A future post…
-Not spend as much money on the hobby as I have in last 2 years, although a Flex 3000 is in works.
-Timonium Hamfest, Timonium, MD.
-Dayton Hamvention. Enough said.
-Sussex Hamfest, I missed this one in 2010 because of work on-call.
-The 2011 antenna projects. See next post.
-..and finally, operate more, build less.

Writing the last post (year in review), I realized I did more station building than actual operation. I’m hoping we have better sunspot performance this year, but now I’m poised to hunker down and start working some DX.

In February I was introduced to 160m and found a great group located in the PA/NJ/DE/MD area who are on 1900khz every night at 8pm. I would finally get to meet them face to face at the Timonium Hamfest in Maryland which would start an every other Saturday tradition of breakfast in Delaware with the guys.

The hexbeam I built back in the previous October (2009) survived the 2ft of snow we saw in March. I would find myself being invited to operate the ARRL DX contest at NE3F’s, which is always fun but also quite an endurance run. I also started operating HF mobile and ended up working VK7ZE on our way to our club station with 100w in a screwdriver antenna on 20m. He was working the states long-path, some 14k miles.

Early in April, I decided to try a 3 element Mosley TA-33 tribander and ended up selling my Hexbeam to Dave (K3GMT). Also in April, I went QRO with a Dentron Clipperton which would be a requirement for 160m in the summer. 1200watts with a set of 4 572B’s. The transformer makes a menacing growl when it’s cranked on 40m, truely a welcomed addition to the shack.

Early in May, Jon (N3INJ) called to tell me 6m was open, of which I didn’t have an antenna for. Within about 45 minutes, I had a 6m delta loop up in the air and started making first 6m contacts. Later that month Laurie and I made it to Dayton. This was our first and plan to make it a yearly event.

I started off the month of June by rotating the polarity of my 2m cubical quad to horizontal and start working 2m sideband. So far it’s been slow, but my furthest stations I’ve worked was Pittsburgh and Connecticut, but the ARRL VHF contest was a blast!

The 1900 guys and I would end up doing a Field Day Expedition to Assateague Island in Maryland. It took a fair bit of planning, governmental politics and a little bit of cash, but we pulled it off. We also pulled off toasting an Alpha amplifier and an Icom 7000. But we all made it out alive with a new experience under our belts and I experienced a pileup the night before on PSK from the beach.

Early in July, I installed the trapped 40/80/160 antenna and start getting S9+40-50 signal reports on 160m, something no G5RV would do. Later that month I would end up in,out and then back in the hospital for a perforated appendix, which made for good rest time for DX at home, but no HT’s in the hospital. I also missed out on IoTA weekend, bummer.

In August I started playing around with satellites and sold the Icom 746 and purchased a Yaesu 847. Just as quickly as I got into this mode, I was out of it, but I walked away with a QSO with Commander Doug Wheelock aboard the ISS while we were mobile.

September my HF configuration came full circle. I ended swapping out the Mosley for my previously rebuilt hexbeam. Luckily for me, K3GMT’s plans for it didn’t work out, and I have my creation back on the roof and working DX like a mad man. At the same time we relocated the 2 meter antennas to a newly installed guyed mast just behind the garage.

October 1st I would wake to find my shack in the basement flooded due to a large rainfall. A normally quiet sump pump would awaken in the night, but a tripped GFI breaker caused it to stop and leave me with a foot of water. No ham equipment was harmed, but the shack ended up being relocated to the dining room. Luckily for me I have a loving, understanding and licensed (general) YL. Speaking of which She and I worked the PA QSO party, but she has not yet given up my Icom 706. I don’t have the heart to take it back, and not that I need it, but it gives me an excuse to buy another rig.

The last quarter of 2010 has been fairly quiet. I’ve been voted into the board for my radio club, working towards DXCC, working more CW and playing around with APRS.

Laurie and I are both looking forward to a prosperous 2011, with me hopefully working HF mobile once again. Hi Hi.

On my particular rig when I enable noise reduction (NR) I tend to get a fair amount of ringing in the filter, an artifact of the older DSP technology. In addition to that Icom’s PBT (PassBand Tuning) only goes so far. My 1900hz filter in the rig could clean up the IF stage of the receiver, but I needed something more to make QRM filled receive audio more tolerable. I also started thinking about the possibilities with RTTY and PSK31.

After listening to Idiom Press’ audio samples on SSB phone and CW, I was sold. I decided to go with the kit form to save a few bucks and experience the challenge of building a kit. Since my last kit (D-Star hotspot) was a success, I was up for the challenge. $90 and 3 days later the kit arrived.

The included instructions were very clear and very consise and the kit assembled exactly like they had stated. One issue I encountered was wrong resistor (miscount). Where I required a 3rd 10k ohm, I had a 100 ohm. No biggie, nothing that I can’t get at my local Radio Shack. Thankfully mine still sells common electronic components. The other issue was trying to figure out the pin ID on the DPDT switch. Unfortunately I soldered mine backwards and the switch is keyed to install in only one direction. All this really means is the UP position is OFF and DOWN is ON. Again, no big deal.

I had most of the kit assembled in the course of 3 hours while I was carrying participating in my usual 8PM net on 1900khz. Today I was able to pickup the remaining resistors and also some audio cables to interface it into my rig setup. I decided to place it between the AF output of the radio (accessory audio output) and the rig audio input of my Rigblaster. This way I could utilize it for digital modes on the computer, which is a direct feed to my monitor speakers. The filter has 2 audio outputs, one for headphones and external speaker audio. The kit gives you the luxury of choosing which size jack 1/4 or 1/8 inch you wish for either function as well as if you want stereo or mono. Since it’s ham radio and the most audio bandwidth I’ll ever hear (from a properly tuned transmitter) is 6khz (on AM), I decided to go mono for both.

Upon powering up the filter for the first time, I was happy to hear the exact results I had heard on their website as well as nothing blowing up (reverse polarity electrolytic capacitors become missiles). The instructions call for you to adjust the internal potentiometer, but I had found the audio to be consistent with it set to the middle.

Check out the photos below and also take a look at the audio spectrum I had captured with the filter in line as well as out.

So far I’m happy with the results and look forward to using it during contests and busy digital waterfalls.
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