FT101 transceiver

[keogaida]

Hi,
I am new to amateur and just passed my Intermediate.
I bought an FT101 and tried tuning it according to the instruction manual, using a 50 ohm Dummy load. I thought I was successful, connected to aerial via antenna tuner, Everything seemed ok seemed to be getting output of 100w on MFJ 949 Tuner meter, But made no contact. Next night deceided to re-tune trans. and try again. When I switch VOX gain to MOX , I can't get 150ma by advancing the drive control.(step 4 in manual) Do you think I have blown the Valves. I suspect I may have spent longer than key time allowed to tune, as I didn't Know what Terms Vox and Mox meant ( I do Now).

Keogaida

[trh01uk]

Well, if you are still measuring 100W of output - even briefly - you haven't blown the valves!

Making a contact requires a lot more than just shoving 100W of RF up an aerial. You have to choose the appropriate band for the time of day, the right mode, and pick a station in a location likely to hear you. In other words, you need to think about your aerial design and the propagation mode you are trying to access.

Richard

[dsergeant]

I suspect you have not got your antenna tuner correctly set so you don't have a matched load. Have you retested with the dummy load? As Richard says, to make a QSO you need to be on an appropriate band for the time of day - at the moment HF conditions are pretty poor and after dark you won't hear much above 30m. What band were you trying, the mode (SSB?) and could you actually hear other stations? When you first get on the air it is better to call other stations rather than call CQ.

Of course your Intermediate licence is limited to 50W output..

73 Dave G3YMC

[Radio Wrangler]

When you are using an antenna tuner with a transmitter having a valve output stage, you have two tuning jobs to do:

First, follow the instructions in the manual for your transceiver to adjust the "tune" and "load" controls so that the transmitter is working correctly into a 50 Ohm dummy load.

Secondly, with the transmitter now connected to the antenna tuner, and the antenna tuner connected to the antenna, you must now adjust the antenna tuner so that it converts whatever impedance your antenna happens to be into 50 Ohms which it presents to the transceiver.

The meter on your MFJ ATU has two pointers which cross over. Printed on the meter scale plate behind them is a scale where you can read off the Voltage Standing Wave Ratio (VSWR) The ATU is set correctly when the meter needles cross very close to the line marked 1:1 You don't have to be perfect, but you should be able to get between 1:1 and 1.5:1 VSWR reading. Most people teach setting up ATUs in terms of VSWR, but there is a simpler way of looking at it as you have one of this sort of meter. One meter needle shows your output power, the other needle shows the amount of this power which is reflected back at your transmitter. You adjust the ATU to minimise the power reading of the reflected power needle. Getting it below 10W is fine.

The process ow switching in dummy loads and doing all this tuning is tedious, but people had to do it if they used an ATU.

Is there an easier way?

Yes, several, but they could be used only under special conditions.

1) If your antenna isn't far from 50 Ohms, the output stage of a valve transmitter can be tuned to drive it correctly without an ATU. You connect your transmitter output to the antenna feeder. No ATU, but also no metering. The signal on the line won't be at 50 Ohms, so if you connected in a meter, its forward power reading would be wrong, and the reflected power reading or VSWR would be high and very misleading.

2) If you have a transmitter with a transistor output stage, it will have a matching transformer as part of its design which sets the transmitter up to work into 50 Ohms al all frequencies in all the HF bands. This means you lose the limited antenna tuning capabilities used in 1) above. So unless your antenna is close to 50 ohms, you have to use an ATU. But you only have the one tuning job to do.

3) If you have a transistorised transmitter AND an accurate 50 Ohm matched antenna, you have no tuning to do but you can only roam the frequency range where your antenna is a good 50 Ohms. This usually means a triband beam on a tower, and gives you the 20m, 15m and 10m bands.

With a good ATU you can use match almost any old antenna, results will vary depending on the antenna (and propagation conditions and whether anyone in range is awake) You have to do more work, but it earns you the greatest versatility.

David GM4ZNX

[keogaida]

Gentlemen I have reconnected the 50 ohm dummy load and started to retune the tx as per instruction manual. With drive control at zero and vox gain switch to mox meter reading should be 50ma , (it is! ) now advance the drive control for reading of 150 ma ! I can't get 150ma even With drive control turned fully clockwise? (This is step 4 in the instruction manual). Help please!

[G4YVM David]

That might not be so strange. These radios are old and often dont perform perfectly. If she's giving 100 watts you aren't doing much wrong. Are you into CW? If so back off the drive and rest the tubes...if not, sigh, then use what she gives and get on 20m or 40m and enjoy.

It's a pity you have no club to help you through this learning process, but if you're rural then you might not have.

David G4YVM.

[G4YVM David]

BTW. What's the aerial?

You say "no contact", quite how are you going about this? The easiest way to start is to answer CQs or tail end aQSO with a strong station.

D

[GMB]

First up, the only manual I have that has a step (4) involving the drive control is the FT101Z. The FT101Z is quite different to the older models - they used the FT101 name because it was popular but FT101Z is actually the next model.

So what actual model are we talking about here?

Also, always monitor RF output into a 50R dummy load while tuning up.
There is a lot of scope for confusing yourself with these transmitters. Small errors with the pre-selector tuning makes a huge difference.
Do check your have TUNE selected and be careful about Morse keys as I think they make a difference.

[Jon_G4XJC]

Just a observation..

By " drive control " does him mean " Carrier " ?

2nd Is he in CW mode (from memory such an transceiver produces only a minute amount of carrier in SSB mode).

De Jon

[Radio Wrangler]

The FT101Z and FT101ZD were actually cut-down versions of the FT902DM up-market model

In these radios the receiver preselector knob also tunes the tank of the driver stage. All is well if the driver valve is the original NEC type, the tuned circuits were designed to accurately track, so when you tuned the receiver preselector, you also tuned the transmitter driver accurately enough.

Sometimes, with other makes of driver valve fitted the driver tank optimum tuning point would differ significantly from the peak position for receiving. This leaves the operator having to move the preselector knob each time on switching between receive and transmit, and vice-versa. Very tedious.

This may be the case with this radio, if it is one of the later sets. Twiddle the receive preselector knob while tuning up and see if this will get it to the recommended PA current.

David

[dsergeant]

Originally Posted by keogaida

I am new to amateur and just passed my Intermediate.

Welcome to the hobby. I assume you had passed the Foundation exam earlier, maybe you didn't apply for a Foundation licence but waited until you had also passed the Intermediate before getting a licence so never got on the air with a M6 call.

Many of us have come in to help, hope you sort out the problem and start having some QSOs. The exact model of the FT101 series would help us and also which bands you have been trying to have some QSOs on.

This weekend is the CQ WPX SSB contest, there will be plenty of stations on who will eagerly be looking for 2E0 etc for a new prefix so you should certainly be able to work somebody. Just give them a report (always 59 in contests...) and a serial number starting at 1. 20m and above during the day, 40m and 80m evening and over night.

73 Dave G3YMC

[keogaida]

My transceiver is an FT101Z My instruction manual is for FT101ZD.
My antenna is a G5RV (half size).
My problem is, No Output.
With 50 Ohm dummy load connected, following the FT101ZD instruction manual (page 13 Transmitter Tuning)
Step 3:- Set VOX gain switch. to MOX position , observe reading on IC meter, it should be 50mA with no drive applied ( drive control fully counter clock wise). Meter reads 50mA, OK!!
Step 4:- Set VOXgain switch to MOX and advance drive control for a meter reading of 150mA. I cannot get meter reading of 150mA even with Drive control fully clockwise. !
THIS IS MY PROBLEM.

[Station X]

How much current can you get?

[Radio Wrangler]

Are you in touch with anyone at the Mid-Lanark Amateur Radio Society? I believe they meet quite near you at the Newarthill community education centre (an old school building). Some hands-on help is much more efficient than typing.

I haven't driven an FT101 for many years and I've operated an awful lot of other sets since that, so I don't trust my memory without having one in front of me.

Usually for tuning I engage vox/mox, select CW mode and use a Morse key to get the transmitter to produce a signal to allow tuning. Some sets have tune switches which can simplify this, but memories merge though a moment trying the likely arrangements sorts things out.

This is a website populated by people with diverse interests in older radio equipment. Help for others is given voluntarily by people from their own free time, and sometimes different people can disagree over the best ways to do things. This is not a manufacturer's help line focused on one particular brand and a small range of current models reading from pre-written scripts for standard problems. The people on here can cover virtually anything that ever used electricity, but you may have to wait until the individuals with the most direct knowledge happen by, or wait for the rest of us to work a few things out.

David

[dsergeant]

You need to set the mode switch to the 'tune' (middle) position first. In USB and LSB positions you will only get drive and output when you speak into the microphone. In CW position you need to have a key connected and pressed to get drive and output.

Dave

[HamishBoxer]

The FT-101 has sweep tube finals (6SJ6's) which I think don't take kindly to being mistuned into a poorly matched load. If you can supply him with a matched load that will take 10 watts, that should be plenty to drive and calibrate an SWR meter. I would recommend that he tune up as best he can into the load at 10W, switch to the antenna to set the tuner for best match on the G5RV, and then to complete the tuning process. A bit cumbersome, but you gotta do what you gotta do.

The 280W referred to in the manual is the plate input power, not the output power. At 60% PA efficiency, that equates to 168W tube output without accounting for any tuning circuit losses. With new tubes, I think they used to run on the order of 120W output or so. And there is no way to control output power on SSB other than lowering the mike gain which, as Steve said, is not a good idea.
With Thanks To Eham

Note you can only alter drive o/put in CW mode Not SSB

Plenty of info on tuning up etc on YouTube

[Radio Wrangler]

The FT101Z and FT101ZD use 6146 finals and are a good bit more forgiving. The earlier versions did use American TV line output valves, but the Z is not a simple derivative of the earlier FT101s it's a cut-down FT902DM, and all the better for it.

Getting that suffix letter was an important piece in the jigsaw. What PA current it can be driven to is the next missing piece.

David

[keogaida]

Thanks gentlemen especially Radio Wrangler.
I'll let you know how I get on in next 3 to4 weeks
Keogaida