49’er & Fake Transistors

A recent posting to Yahoo's 'GQRP' reflector spurred discussion of the growing number of fake transistors being seen on e-bay. A builder enquired about the low efficiency noted in his recently built Chinese '49er' kit.

I recently bought one of the Chinese Forty-9er transceiver kits off ebay and on receive it works well. It certainly transmits, but the power is down to 800mW and the driver transistor is getting very hot. I'm not expecting a lot of power from it, but power claims are 1.8W to 3W. I'm more concerned about the hot driver transistor. The following link shows the circuit diagram.

http://www.ebay.com/itm/DIY-kits-Frog-Sounds-HAM-Radio-QRP1-8W-CW-Transceiver-Receiver-7-023MHz-/121507448525

I've checked for spurious oscillation (a problem I've had before), but can find nothing. Does anyone have any ideas for why the transistor is getting hot?

It was suggested that the transistor in the PA may not be up to specs and even be a 'fake' as these types are commonly noted on e-bay, selling for prices that are too good to be true.
 
Without taking a close look at your built kit, my suspicion would be the PA transistor. The schematic provided in the listing to which you provided a link shows a D882 as the PA transistor. This is a 2SD882 transistor is a garden variety audio amplifier transistor at best. Some data sheets show a fT of 100 MHz. These 2SD882 transistors are listed and sold by the handful on eBay for a couple of dollars for a dozen (plus and minus). Perhaps substituting a good quality better suited to RF duty transistor would be the ticket. Perhaps something like a 2SC1971. But before you start looking for listings for a 2SC1971 be aware of the fake ones that also quite prominent on eBay and sell for only a few dollars. On eBay search for "eleflow" this is brand name of a manufacturer who is making good quality substitute devices for a number of the popular CB and HAM radio PA transistors - user name on eBay is weazle66. His listing for this particular device is 27187465609 BUT you will pay as much for this replacement PA transistor as you did for the kit ... To find out more about some of these fake replacement transistors, search for "FAKE 2SC1969 RF transistor" or "FAKE NEC & MITSUBISHI RF TRANSISTORS" on youtube. The poster has a number of such video postings. Searching Google for "fake transistors" or such will turn up much interesting.

The problem was eventually sorted out by exchanging transistors:

Firstly, thanks for all your help. Initially, I replaced the Chinese PA transistor with a BD139 and that increased power output to 1.2W and reduced the heating of the driver. Key down and it took perhaps 20s to get "finger hot", rather than 10s. Tonight I changed the driver transistor to a 2N3904 as used in the original Forty-9er and the driver heating seems to have gone away. A small heatsink on the PA transistor allows it to run at 1.4W output for 30s of keydown without any drop in power or the heatsink getting any more than warm.
Thanks for all your help and I hope this helps someone else.

A search of Youtube videos shows several builders that have split some of the RF devices open in order to compare die sizes of suspected fakes with the real thing:


Earl Andrews, VE3GTC, has gone to considerable effort to test and compare many of his transistor purchases and indicates that there are a lot of devices coming out of China that are outright fakes and have no hope of meeting the specs that you might expect. His interesting website has a lot of details about testing as well as a very comprehensive 'for sale' list of reliable devices. Earl also suggests using caution when buying e-bay Chinese electrolytics as his measurements of ESR values indicate that many do not pass specs.

If you have purchased fakes or have found a Chinese source of the real thing, please let us know ... I'm sure there are plenty of dealers selling the real thing out there.

Steve McDonald, VE7SL, is a regular contributor to AmateurRadio.com and writes from British Columbia, Canada. Contact him at [email protected].

User Hostile! Radios that you love to hate!

Three band HT Radio, 2 Meters, 70 CM and 6 Meters

Three band HT Radio, 2 Meters, 70 CM and 6 Meters

“I hate this radio”

Have you ever said this?

I certainly have. Some radios are a joy to use. They are intuitive, easy to use and you don’t ‘NEED THE MANUAL’ every time you want to change something!

HT’s seem to be the most ‘user hostile’ radios available to hams. I know! All HT radios should have certain things, VFO, on off knob/button, volume control and keypad, and in my opinion, they should not be so difficult to use that you need to read the manual every time you want to do, what should be a simple task; change CTCSS tone of a repeater, for example!

When HT’s were reduced in size, they became more complicated to use. Menu systems were instituted. They were further reduced in size and menus were multi-layered! How many times have I yelled at my HT after holding button a for 1 second, then within 4 seconds, tried to press button 2, for 1 second but no more than 2.5 seconds, while doing 3 pirouette turns on my left foot, only then, can I use my radio. That same button has 3 functions now a days. Press it once for one thing, press it again within a specified number of seconds and you get another function. Press and hold it and you get yet another option.

Enter the English Translation, manual! Poorly translated from Japanese, but at least its in English!  (With many pertinent things omitted!)

Why do manuals go to great lengths to tell you in great detail everything that you ‘don’t want to know’ and will most likely never use or use very seldom?

But tell you want you NEED TO KNOW, naw!  Tell you how to ‘undo’ something? That would make it too easy!

Actually, I really like this VX5-R HT from Yaesu. It’s a love/hate relationship, however! So very handy, it fits in the palm of my hand, has lots of memories, and many many nice features. Accessing those features is not always easy, especially without the manual right in front of you. If you ever push the wrong button, and send it into ‘never-never-land’, its hard to un-do what you just did! One thing that was left out of the VX 5 is a memory clear feature!  That omission makes life with this radio difficult at best!

You cannot return a designated memory channel to its ‘no data’ state. The only thing you can do from the radio itself is to overwrite that particular memory with another frequency!

 

2 Meter IC V8000

2 Meter IC V8000

I’m not picking only on Yaesu!

This Icom V 8000 is the most ‘User Hostile’ radio that I have ever owned.

Not only is it difficult to use, but it has problems as well. The mic is notorious for a mechanical problem with the PTT button, and the external speaker jack does not work well. Unfortunately, the external speaker jack is where you have to plug the programming cable in to program the radio. The Icom program for doing this is also ‘user hostile’ BTW!

Editing and Cloning Software RT Systems I bought software and cable from RT systems to program and manage the Icom T 70-A. The HT and its programming software arrived yesterday.

 

IC T 70 programming software and cable

IC T 70 programming software and cable

Icom T70 A with spare battery, left, drop in charger, and speaker mic

Icom T70 A with spare battery, left, drop in charger, and speaker mic

 The Icom T-70-A, is the replacement radio for the Yaesu VX 5

It will replace the VX5 as my ‘go to’ HT. Just last night, I picked up the Yaesu VX5 the wrong way, mashed some buttons on its face and sent it into never-never-land!  Try as I may, I could not undo it with normal button press. Since the radio has an RT Systems program and cable on its way, I went nuclear, and reset the processor. Finally, the radio was operational once more. It needs programming of course but the display is no longer stuck!

It programmed the Icom T 70-A radio to my specifications with only a cursory reading of the manual. The radio is intuitive, easy to use and has some great features. RT Systems Programming Software and Cable

 

IC 7100 and Touch Paddles

IC 7100 with Touch Paddles

Funny, I just installed an Icom 7100 mobile HF/VHF/UHF/MF radio in my truck. That radio was ‘done right’ by the manufacturer! Its easy to program and use, so there is no need to keep the manual handy for simple tasks. I run mobile CW/SSB and VHF repeaters with it. If there were any UHF in the area, I’d have that programmed in there too. Its a joy to use!

This photo shows the IC 7100 on a modified clip board held in place with bungee cords. So far, I have not seen the need for programming software. That said, there is an SD card on board this radio. It can save the settings to the SD card. I have not explored this avenue yet. It would be nice to keep a copy of the settings on an SD card and on my laptop for future use. Something unexpected can happen. Spare radio data would come in very handy then. Replacing all the settings would be very easy with the programming/clone software. RT systems sells that one too.

Do you have a radio that you love to hate? 


Ernest Gregoire, AA1IK, is a regular contributor to AmateurRadio.com and writes from Florida, USA. Contact him at [email protected].

49m Canadians QSL’d

My recent interest in the remaining Canadian shortwave broadcasters (see The Lonely 49m Canadians), led me to try and QSL a couple of the stations. Seeing as how the CBC outlet on 6160, CKZU-Vancouver, is almost line-of-sight and just on the other side of Georgia Straight, I haven't yet worked up enough nerve to send a reception report describing their S9+40db signal!
When initially listening for the station in Calgary, CFVP on 6030, I was never able to detect more than a weak, watery carrier. Conditions must have been much worse than I had suspected as normally this path is an easy one. A few weeks later, when I started looking for them again, I found their 100 watt signal to be quite robust, several days in a row. In the early afternoon, their signal was peaking 5x7 and continued to build until Radio Marti in Florida signed on a few hours before sunset and dominated the frequency for the rest of the night.

An e- mail report to long-time veri-signer and Ontario DX Association mainstay, Harold Sellers, brought a quick e-mail verification. I was hoping that CFVP would still be issuing a paper QSL but nowadays that is getting to be a rarer and rarer policy.


Harold also reports the following details about CFVP:

CFVP broadcasts the programming of AM 10-60, CKMX, 1060 kHz. The transmitter site is located east of Calgary, just off Highway 22X Marquis of Lorne Trail, on Range Road 290. The Google Earth coordinates are 50 54’02”N 113 52’26”W.
CFVP Tower courtesy: Harold Sellers
Since I started doing the QSLing there haven’t been very many CFVP reports; more for CKMX. Overseas reports have been from The Netherlands and Germany.
Next on the the list was Toronto's CFRX, 6070, whose signal has been strong, starting well before local sunset. Veri-signer Steve Canney, VA3SC, requested a written report and an SASE which was quickly rewarded by a rare and very real paper QSL.



Steve reports that CFRX is simulcasting CFRB (1010kHz) using 1000 watts into an omnidirectional vertical antenna. They have received several reports from Europe over the many years that he has been sending verifications.

Now to tackle CKZU!

Steve McDonald, VE7SL, is a regular contributor to AmateurRadio.com and writes from British Columbia, Canada. Contact him at [email protected].

ID-880H in the jeep

Tonight was a successful ham radio night….the 880 I bought from fellow ham WC9V was installed without incident in my daily driver jeep yj. I’m using a 1/2 wave antenna mounted on the spare tire rack. Finding a suitable antenna mounting position on a jeep is no easy task. My usual plan of drilling a hole and installing an nmo mount was to going to work. It’s going to be nice to be back on DSTAR and the local repeaters during my commute!

Michael Brown, KG9DW, is a regular contributor to AmateurRadio.com and writes from Illinois, USA. Contact him at [email protected].

ID-880H in the jeep

Tonight was a successful ham radio night….the 880 I bought from fellow ham WC9V was installed without incident in my daily driver jeep yj. I’m using a 1/2 wave antenna mounted on the spare tire rack. Finding a suitable antenna mounting position on a jeep is no easy task. My usual plan of drilling a hole and installing an nmo mount was to going to work. It’s going to be nice to be back on DSTAR and the local repeaters during my commute!

Michael Brown, KG9DW, is a regular contributor to AmateurRadio.com and writes from Illinois, USA. Contact him at [email protected].

10m BitX transceiver

I notice that someone has created a 10m (28MHz) version of the BitX transceiver. Yes, all would like more details but we don’t know who you are!

Anonymous said:  “I have successfully designed and built a 28MHz version of the BITX transceiver. The main reason for this project was to drive homebrew transverters for 6, 4 and 2Metres. Contact me if you would like details.”


Roger Lapthorn, G3XBM, is a regular contributor to AmateurRadio.com and writes from Cambridge, England.

Fourbox transceiver

G7CKF’s Fourbox

Jenny, G7CKF  has now taken the 2m Fredbox design and created a 4m version called the “Fourbox”.

Hi Roger,

    I feel I should drop you a line with my thanks and the link below, I’ve used your QRP AM transceivers as the basis for a 4M transceiver and published it on my blog. I’ve come back to amateur radio after a 20 year absence and since construction was always my main interest in the hobby I reached for the soldering iron.
http://thekeywordgeek.blogspot.co.uk/2015/05/a-transceiver-for-not-lot.html
There is no sparkling new insight to be had from it as it’s pretty much your fredbox with slightly bigger coils. There is no crystal because I am cheating and using a Raspberry Pi clock generator to make my 70.260MHz.

My QTH is IO91lw, between Bicester and Buckingham and rather low lying. Very little 4M activity hereabouts, sadly, so the chances of my actually working anyone with it are slim. But that’s not really the point of building, is it.

Anyway, hope you find it of interest, and thanks again for sharing your designs.

Jenny, G7CKF


Roger Lapthorn, G3XBM, is a regular contributor to AmateurRadio.com and writes from Cambridge, England.

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