SG Lab 23cm Transverter - Anyone heard of them?

[VK1JA]

G'day All,

For a while now I've been thinking about delving into the higher bands, and picked up an older (albeit fully functional) Puma Bit Zero 23cm transverter to start playing with. The unit is a great starting point for anyone starting at 23cm, but in the true fashion of new gadgets and the great time waster of surfing eBay, I stumbled across the following 23cm transverter and took a leep of faith and pulled the pin and bought one.

The specs and features look very good, and I'll be very interested to see how it performs. All going well it'll be a nice starting block for a 23cm setup that I can use for a while to come.

The web link is here http://www.sg-lab.com/TR1300/tr1300.html and the link to the eBay sale is here (noting that it appears you can order direct from them as well)

http://www.ebay.com.au/itm/Transverter- ... 1377435618

The last 2 times they have listed 4 (?) units for sale on eBay at a time, all units were sold within 24hrs, so the seem quite appealing. Lets hope (for my sake) that they function as good as the specs.

I've attached the PDF, and I picked up that my purchase should be the v2.2b which has one or two small enhancements

It may be a while until I have a 23cm setup running, but I'll do my best to give updates, both good and not so good.

I'll be interested in hearing from anyone that has had any experience with these transverters, or even SG Labs in general.

73

Jayson
VK1JA

[ZL1RQ]

HI Jayson, I am also interested in one of these, please post your thoughts once you receive the transverter.

Alan
VK4WR

[VK1JA]

Hi Alan,

Certainly will.

So far (albeit early days), their communication has been very prompt. The 'package' should turn up in about 2 weeks, so I'll give you my impressions when it turns up. Then once I get it operational I'll give you a run down. 23cm activity in VK1 is quite low, but I'll see if I can scrape a person up!

[VK1JA]

The transverter turned up before the estimated time, and looking at the post stamp, they posted it the day after payment was made.

Now I have ordered the adaptors needed to test and get the transverter running, so a bit more of a wait until I can let you know what the performance is like.

Cheers

Jayson

[VK4VU]

Hi Jayson,

I also have one of these on the way. I must admit they look to be very well designed and assembled from what I can see.

Incidentally, I inquired about a small change to the PLL programming to allow 1152 or 1151 MHz to be selected as the LO (rather than 1152/1150 MHz), since I wanted to use 145 MHz as the IF for 1296 MHz.
Hristiyan said it was no problem to do this, so this is being supplied as Version 2.2c.

BTW have you been able to establish the PLL reference oscillator frequency, and how easy it might be to use an external high-stability reference if it was available ?

73

Rod VK4VU

[VK1JA]

Hi Rod,

Please let me know how you go! It appears that these transverters are relatively new to the market and hence there's not a lot of info out there about how they perform. You and I may well be the VK test bunnies

I haven't even powered mine up as yet, and my test gear comprises of a Fluke multimeter.... The specs do say that it has a high stability TCXO, and the LO at 20 deg C is stable to +/- 1ppm, and -20 to +70 deg C is +/- 2.5ppmm so it'll be nice to see if it performs as such. Saying that, I have a GPSDO (Trimble Thunderbolt) that, if I could use, would come in handy.

You are correct about the build quality, very nicely assembled and well laid out.

Just curious how you intend to install yours? I'm considering mounting mine (remotely) close to the pole that the antenna will go on. I have a 12v power supply near that location, and I can mount a relay switch (N type) and use that to switch between 2m and 23cm etc. In my scrape pile I have a 10w 23cm amp that I'd like to use with it as well, but the amp has a max input of 1w, and the transverter has a 2w output, so I'm trying to track down a cheap SMA or N type 3db attenuator as well...

Cheers

Jayson

[PA0P]

Hello all,

Triggered by this article and the price of Euro 150 including shipment I have ordered a unit and did get it delivered within 4 days (The Netherlands), together with a free 23cm HB6CV antenna and plugs for power and PTT.
The transverter is very well built and it was very easy to get operational by driving it with a Quansheng porto at 1 Watt.
Output as measured is close to 3 Watt and the frequency accuracy is very well, also see no problem with the sensitivity as I could receive beacons up to 250 km away (GB3MHL/B) with a simple 15 element HB Yagi.
With the option for split TX and RX one can save a coaxial relay when using an external power amplifier. The transverter even has a built-in sequencer.
This is also an ideal unit to use portable due to the small size, light weigth and low power consumption.
Built-in features are quite similar to the 10 times more expensive Kuhne transverter!
Looks as this product is a winner at the current pricing.

Cor PA0P

[VK1JA]

Hi Cor,

I'm glad the SG Lab transverter is working well for you.

The transverter does have a lot of good features built in - one extra feature that would be nice would be adjustable output power so you could match the output to your amplifiers input requirements. But I'm certainly not complaining because a simple attenuator can fix that problem.

One feature that is interesting is the built in directional coupler and built in SWR indicator. And further to this, I note that they have incorporated a three pin header with voltage outputs for FWD power, Reflected power and Ground. I'm guessing that if we can figure out the voltages for these outputs we could scale them to a meter display.

Cheers

Jayson

[PA0P]

Hi everybody,

Have communicated with Hristyan from SG-lab and he has tested the possibility for a LO choice of 1152/1154 MHz. He confirmed that this is no problem at all to deliver.
It is a better choice for European countries where the repeaters do use 1270.xxx/1298.xxx MHz channels and where a lot of sets only can transmit between 144 and 146 MHz. (at least my ICOM275H and TM255E do so). Do not know if this is also valid for VK...

73 de Cor, PA0P

[VK1JA]

Hi All,

Just an update, I sent an email off to Hristiyan asking him if the power output can be reduced down so to not over drive the amp I have, and it is possible! The TX power adjust trimmer can be adjusted to reduce the output - it seems this is the 'gain control' of the output for the transverter. Hristiyan did mention that if you do reduce the power down then expect the TX LED to indicate orange - which means the output power is low (makes sense...). He also mentioned that if you reduce the input power too low (to get a very low output power from the transverter) the onboard TX switching may not engage, so you may need to hard switch it via the PPT sense in these cases.

This means I'll be able to use the 1w in, 10w out, 23cm amp I have here I've also got a 23cm 18w Minikit amp in the draw waiting to be built! I've still yet to buy a case/heatsink/fan for the MiniKits kit, so that'll be far down the track at this stage...

Another thing that Hristiyan sent me is the voltage output of the FWD pin header in relation to the output power - very useful if you don't have a 23cm power meter The voltages are;

Output
0.5w - 0.69v
1.0w - 1.02v
1.5w - 1.27v
2.0w - 1.48v
2.5w - 1.64v
3.0w - 1.82v

The figures were taken at 21c temp with a supply voltage of 13.6v. Remember that these values may be different for each individual transverter, but it will give you a good guide. And yes, using a supply voltage of 13.6v the transverter can reach 3w output as mentioned above Also note that the output watts v output voltage is fairly linear which is nice to see.

I'm still waiting for the cables and adaptors to arrive so I can get the transverter up and running in a permanent setup.

I must say that I'm very impressed with the responsiveness and willingness to help of Hristiyan

[VK1JA]

Another quick update on these good little transverters in regards to the FWD/REF voltage header - the REF voltage output will have the same voltage values as the FWD as the directional coupler in them is symmetrical.

BUT, one thing to keep in mind (I found out from experience recently) is when you are measuring the voltages and you have the multimeter leads near the transverter, then RF will get into the leads and give false readings! At one point the SWR light was lighting up orange for me (moderate SWR) with a measured voltage on the FWD header of 1.80v, and a measured voltage on the REF of 1.80v as well!! But it was simply because a heap of RF was being caught by the multimeter leads.

The good thing is that you really don't need to monitor the voltages on the header as it's pretty much a set and forget thing, but you'll always have a visual indication from the two LED's that show input and output 'health' in the green/orange/red colours.

I'm almost ready for mine to be setup and then track down another VK1 for testing - I just need to run one extra cable. The 3w output may make it a challenge for me to make contacts as the yagi is only a small 9 element (?) cheapie from eBay (see my QRZ page). But then there's more incentive to get an amp setup up for 1296

How is everyone else going with these transverters - PA0P - VK4VU - VK4WR ?

[ZL1SWW]

Hi Jayson.

That unit sounds like a nice little system and compact enough to get up the mast.

Re your comments about possible difficulties for 1296 contacts with 3 watts. You may be surprised with what you can do with the power as I have worked another person running about 50 milliwatts from a raw transverter borad that had a MAV11 device in it. We were able to have an easy contact over a 150 km path which was not totally optimal. Used 27 el loop yagi at my end and maybe the other end was the same but can't remember.
I've often had contacts with another friend of mine at 337 km where he is running 1 watt and no probs with copy. Admittedly we were at highish spots. Me at 375 m asl and Harry at 800 m or so.

FYI if interested, check out the video that shows the kind of copy you can expect.



http://www.youtube.com/watch?v=rv1u5sEWKnc

Cheers,

Simon
ZL1SWW

[VK2DVZ]

Hi Jason,

As Simon has stated, don't be dismissive of giving lower power levels a try on the 23cm band.

I have worked a number of different ZL an VK stations who have at the time been running 10 watts or less in power. The recent January VK-ZL openings saw ZL3TY from Greymouth and ZL1AVS (remote station located at Muriwai) both running 10w worked and in my logbook. Yes, other higher powered stations were also worked, but higher power is not always needed. Recently I again worked Kerry VK2BXT located near Camden over a distance of about 308km, with his 7 watts at the feed point. A 1 watt station, portable at Sydney's Northern Beaches was also worked some years back. (I am located a little NE of Taree - near to the Taree Airport).

Whatever power you have available, give it a go - you may be pleasantly surprised by the results. Having worked several stations from the Canberra area and beyond in the past, I look forward to our first contact on 23cm Jason.

Good luck with your transverter project.

.

[VK5DT]

Thanks for sharing Jayson.

I've been keen to get up and running on 23cm and this might be the ticket.
Would be great if they made a variant with a repeater offset of 20MHz for Oz rather than the 6MHz and 28MHz offsets.

Cheers
Darren

VK5DT

[VK1JA]

ZL1SWW,VK2DVZ - thanks for the info and encouragement, it's good to know that 23cm can be just as exciting as the other bands.

VK5DT - the offset frequency is one thing I didn't check on before I made the purchase but I dare say that if you contact Hristiyan and ask him to make a 20Mhz offset version, he would!

Well, today I had my first contacts on 23cm using the SG Lab transverter. I was lucky enough to catch Rod VK2TWR and Rob VK1KW on 144.200 playing with the morning AE.

I was very doubtful of making a contact with VK2TWR as Rod is 125km SE of me over the Brindabella ranges and my set up at the moment is a cheapie ebay 9 element yagi (all of 30cm long) at about 6m in height. My cable is 11m of LDF450, then 6m of LMR400 to the antenna. No pre-amps, and running barefoot out of the transverter which is about 3w, so at a guess about 2w at the antenna. Plus the fact I had no idea if the transverter was on frequency, or even sensitive enough to hear Rod, let alone for Rod to be able to hear me at the 125km distance.

So I go ahead and select the transverter menu item on the TS-2000 and plug the transverter input into the 144Mhz output of the radio, and low and behold I hear Rod, VK2TWR super super faintly calling me, then I realize I've still got the attenuator on the TS-2000 switched on (on 2m I run a boom mounted preamp and turn the radio preamp and attenuator on, this gives me the best results without overloading the front end of the TS-2000). After turning the attenuator off Rod came up to a 4 by 1 and gave me the same report back. I dare say Rod was doing all the hard work with his setup, but I was surprised to make the 125km trip with such low power AND the transverter worked first go, smack on frequency !!

Rob, VK1KW was about a 5 by 3 once I turned the antenna around to point at him. Rob is about 26km away and we have a few hills in the way.

My first thoughts of the transverter are very encouraging, but I now know that a decent antenna, mast mounted pre amp and more power will go a long way

Jayson

[VK5DT]

Hi Jasyon,

Well I took your advise, I have finally got around to contacting Hristiyan on building a +20MHz repeater offset variant and he said no problems.
It should be going through the final stages of testing as we speak.
Can't wait to get on 23cm to have a play

Cheers
Darren

[VK1JA]

Great stuff Darren!

We don't have any 23cm repeaters in VK1 so the offset wasn't a concern, but it's good to know that they can customise if need be.

Let us know how you go when you get the transverter in and running.

Cheers

Jayson

[VK5DT]

Hello Jayson,

Well after a few additional months of R&D, my Ozzie version of the SG-Labs transverter has landed just over a week ago.
(Hristiyan just got busy and I told him not to rush).
I have to say for $195 + $11 shipping USD (AUD $237 to my door) it's extremly good value and for waiting so long Hrystiyan added a small HB9CV PCB antenna as a gift (5dBi gain)
Hyrstiyan had to modify the L.O. frequencies from the standard V2.2 and added a fifth jumper. Jumper 5 wasn't a real jumper it is pin 2 of the micro and he said it could be left (off) or soldered to pin 3 (on). See "Transverter_1296_Freq.pdf" for the jumper switching.
Last week I verified the simplex mode and tonight the duplex (+20MHz shift) on the Summertown repeater.
Very happy I could hit the repeater, which is about 25-30kms from Gawler, with the HB9CV strapped to an old grid reflector galaxy dish as the feed.
Looking forward to using it more.

73's
Darren

[VK5PJ]

Hi Darren,

25-30kms from Gawler
73's
Darren

No sure if we have crossed paths, I come to Gawler each day for work from the Barossa, are you active on VHF SSB?

Regards,
Peter, vk5pj (Tanunda / Angaston area)

[VK5DT]

G'day Peter,

Mainly on HF, but getting very interested in working the higher bands.
Not much VHF SSB, as only have a vertical 2m/70cm collinear in the air.
If I hear you on the bands/repeaters I'll give you a shout.

Cheers
Darren