Frequently Asked Questions

Hi again, do you leave the 40 MHz clock of either TR7 or R7 untouched? The (high) stability of your VFO suggests you use another separate clock. Is that so?

Yes. We do not modify the TR-7 or R-7. The quoted stability is for our output. Our output is 5.05-5.55 MHz. Our unit is basically a DDS version of the RV-75 with some added features and is "plug and play". We do not supply a 40 MHz clock.

Hello... Do you know what the difference is between this unit and an FS-4?

We have no knowledge of what an FS-4 is. The RB7501 is a new product of Misty Hollow Enterprises.

Does this unit include the cables for BOTH the TR-7 and the R-7, so that it can be used -- as it stands -- with both units?

It includes a "Y" type cable assembly that will allow you to connect both units together. There is also a switch on the RB7501 that will allow you to toggle between the units. If you wish to use it with a TR-7 only, then you leave the R-7 cable unconnected. Then the R-7RX/TR-7RX switch on the front of the unit should be set to the TR-7RX position. We can also sell you the cable normally supplied with the TR-7500 which connects to the TR-7 only and is compatible with the RB7501 for $25 additional cost (cable wiring information is supplied with the unit so you can build your own).

If I am not satisfied can I return for full refund?

Sorry. The posted return policy states EXCHANGE only.

Hi. Very interesting device, I notice you have a version for TR-7 and R-7 can this be slaved to both rigs like the RV75?

Yes. We add a switch to the front of the RB7501 to allow you to select whether the R7 or TR-7 receiver is controlled by the unit. The transmitter is always controlled by the RB7501 if it is on.

Hello, I am curious how this item is different from my Drake RV-7 remote variable frequency oscillator (VFO) for the Drake TR-7 transceiver?? I have two Drake TR-7's and I am curious about this item.

The RV-7 is just another Drake analog VFO. It has the same stability as the internal permeability tuned oscillator (PTO) in the TR-7. The RV-7 allows the TR-7 to transmit/receive on different frequencies. Drake used to make an RV-75. This was a phase locked loop synthesizer. It was more stable than the RV-7, but is no longer available. Also, the RV-75 would not work with the R-7 unless you purchased a special cable, which is also no longer available. Our unit uses a digital technique called direct digital synthesis to generate a stable signal that does not drift and replaces the RV-75. We have the additional capability to provide different transmit/receive frequencies. which are displayed on a liquid crystal display (LCD). Our unit has been successfully tested by buyers in the U.S., Italy and France with two more units in route to Germany.

Will this VFO work with the Drake TR-4310 transceive, which is very similar to the TR-7A unit?

We haven't tried it yet. Does this transceiver cover the same frequency ranges as the TR-7 and does it have the connector on the back for the RV7 external VFO? If you can send me a e-mail with a copy of the manual page that shows the connector pin out, we can get a pretty good idea. In this case, we are willing to allow you to return the unit within 10 days if it doesn't work for you. The TR-4310 is a commercial version of the TR-7. The RB7500 should work with it.

What is your return policy if not satisfied with item?

We warrantee our work. We will repair or replace a faulty unit as long as it was operated per instructions. We do not allow for returns, should you change you mind about the purchase.

Has there been a product review done on this item by QST?

No, but we are sending a unit to CQ for possible evaluation.

Do you have plans for a unit for older tube types? Like the Drake C Line, or Drake TR-6. I would really like one for the Drake TR-6.

We have to have access to a TR-6 or C-line, which is currently not available to us. We are looking at other units, but do not have anything available at this time.

Hello there. Can you ship to Italy via Air Mail Parcel Post ?

Yes. That is $22.75. Insurance extra.

Hi, does the RB7500 have previsions for a RS-232 connection, for possible computer control and memories?

Sorry. No.

Hello, last week I bought the same item ebay number 5764778085. When did you really send this? It hasnīt arrived yet.

We received notice on the 11th of April that your check was in the mail to us. We mailed the unit on the 12th (prior to actually receiving the check). We have been told that it takes about 10 days to make it to France or Germany by Air Parcel Post.

I presume it (RB7500) hasn't got some sort of an I/F such as RS 232C or other for computer control, does it?

No. This unit is basically a replacement for the RV-75 with some additional fratures like split mode and a display.

Concerning connection to both the R-7 and TR-7 combined, how do you handle this, by charging US$25 on top of the price?

We have a unit that is called the RB7501 and has some additional circuitry plus a much more complicated cable so it costs us more. If you want this option, let us know and just add $25 to the price.

Is this to be connected to a TR-7 as an RV-75 or a RV-7 VFO, e.g. does it deliver 5 to 5.5 Mhz ?

Yes. It is basically an RV-75 with additional features. It is a DDS rather than an analog synthesizer.

Do you make one for a Drake TR4?

We are currently working on the design for a unit to support the TR-4 and/or TR-4C units. It will be similar, but will have to include calibration software since the TR-4 uses imprecise overtone crystals for 40, 15 and 10 meters. We currently expect it to be available about the middle of June.

I saw the ad for your RB7500 VFO unit in CQ Magazine (April 2005) and am very interested in knowing more about not only that unit, but all your VFO modules, especially any that can be used with modern Icom, Yaesu, Alinco, and SGC radios. Your ad states that other radios are under development. The reason why I feel that your product(s) would suit my needs is because I wish to add bands to some radios and/or extend frequency coverage on others. I am particularly curious whether or not your units can cover the 60 MHz, 222 MHz, 1.2 GHz (and even 11 meters, for that matter) bands, as it is getting increasingly difficult to find (222/900 MHz) equipment for some bands.

Our unit was designed to correct frequency drift problems in older HF radios. Newer equipment will not benefit from this device as it generally has stable oscillators already built in. This unit is only a VFO and actually covers 5.05 to 5.55 MHz as needed by the TR-7. The additional units to which we refer are other Drake units such as TR-4, R4-T4 series, Swan 500 and 500CX, etc. We do not add frequency coverage beyond what the radio itself was designed for. The bands that we cover include only those that were originally designed for the radio. We do not do anything above 30 MHz. We hope this helps and look forward to hearing from you again.


Last Updated May 06, 2005 by KB5OQX